So, some of them should be MIRVed if the threshold of 2000 warheads is to be maintained. Otherwise deployed warheads will fall well below this level.
This is more or less in accordance to the Sokov prediction:

"The SRF will feature silo-based MIRVed ICBMs with three warheads each and single-warhead mobile ICBMs with defense-penetrating warheads. Overall, this posture could be quite survivable."

http://cns.miis.edu/pubs/week/051109.htm

I don't think they will be MIRVed (although it may be an option at some point). And as far as I understand, the target level is 1500 warheads, not 2000.

Павел! Сдается мне, что скорее всего ты ошибаешься, когда ведешь о том, что из 69 "Тополей-М" 18 будут шахтными, а 51 - мобильными. Ведь министр обороны Сергей Иванов, находясь в ПО "Баррикады" (Волгоград) вел речь исключительно о РС-12М1, которые будут закуплены для РВСН в 2007-2015 годах. С учетом трех РС-12М1, закупленных в этом году (они войдут в состав первого в РВСН дивизиона 54-й рд в Тейково) общее число РС-12М1 в 2015 году составит таким образом 72 комплекса. А с учетом 50 шахтных РС-12М2 в 60-й рд в Татищево общее число "Тополей-М" будет в 2015 году равно 122. Учитывая, что к тому времени каждый "Тополь-М" должен будет нести по шесть ядерных боезарядов, их общее количество составит 732.

Does anybody know if there are any remaining single warhead R-36M2's remaining in service?
Jon Grams

Иван Сафронов:

I would be very surprised if the Topol-M missile will ever carry more that one warhead. While it may be technologically possible for the system to carry the six warheads you suggested, it makes little practical sense to do so. MIRV silo missiles are only targets and "protect" Russia no better than single warhead missiles. Russia will be a world power with 100 ICBMs but no greater power if it has 1000. Just my thoughts.

Frank Shuler
USA

По словам замглавкома РВСН по вооружению - начальника вооружения РВСН генерал-лейтенанта Виталия Линника к 2011 году из боевого состава РВСН будет выведено около 200 БРК SS-19 (УР-100УТТХ, РС-18) и SS-18 (Р-36МУТТХ, Р-36М2, РС-20), то есть все имеющиеся сейчас МБР с РРД. Кроме них в боевом составе также не останется 270 мобильных "Тополей" (РС-12М).

В результате из имеющихся сейчас в РВСН 13 ракетных дивизий (к концу этого года будет 12) к 2016 году, по словам главкома РВСН генерал-полковника Николая Соловцова, останется лишь 4. Надо полагать, что одна из них будет вооружена 50 "Тополями-М" (ШПУ), а три другие - 69 мобильными "Тополями-М". Кроме того к 2016 году у России должно быть 5 атомных подводных стратегических ракетоносцев проекта 955 "Борей". На каждом - по 12 ракет "Булава-М" (РСМ-56) с 6 боеголовками каждая. Всего - 360 ядерных БГ. Наконец, в ВВС будет иметься 80 стратегических бомбардировщиков Ту-160 и Ту-95МС, которые смогут поднять около 700 крылатых ракет. Из этого следует, что к 2016 году Россия будет располагать почти 1800 (732+360+700) ЯБЗ.

Safronov Ivan:

I guess the only question in this debate is whether the SS-19/SS-18 systems will be active post-2016 and, if so, will a successor ballistic missile system be developed to replace them in the future? All this is left up to us to speculate. Based on world politics, the needs of the Russian military and future trends, I think the SS-19/18s will be removed from inventory and not replaced somewhere around the 2016 timeline. I also think a new Russian strategic (nuclear) cruise missile will continue in development and be introduced around 2016 that will extend the life of the Tu-160-Tu-95MS fleet well into the future. I agree on the 360 Bulava warheads and the 700 cruise missiles but think the land-based Russian ICBM force will be around 130 SS-27 Topol-Ms. My prediction is the Russian nuclear inventory in 2016 will thus be around 1200 strategic nuclear weapons.

Frank Shuler
USA

For those who don't read Russian, I'll summarize Ivan Safronov's comments:

The main point is that the 69 missiles mentioned by Ivanov, are mobile Topol-Ms only. This number also does not include the three mobile missiles to be deployed this year in Teykovo. This means that by 2015 Russia will have 72 mobile and 50 silo-based Topol-Ms. With six warheads each, they will add 732 warheads to the Russian strategic force.

Ivan also quotes Vladimir Linnik, head of the armament of the Rocket Forces, as saying that by 2011 Russia will decommission about 200 SS-19 and SS-18 missiles, which means all liquid-fuel missiles. 270 SS-25/Topol missiles will be decommissioned as well.

As a result, by 2015 Russia will have four missile divisions (presumably one silo-based Topol-M and three mobile Topol-M). In addition to this, Russia will have five Borei submarines, with 12 Bulava missiles (six warheads each) and 80 strategic bombers with about 700 cruise missiles. This means that Russia will have about 1800 warheads.

What can I say? I don't know. As I said, other configurations are certainly possible, so we may well see 72 mobile Topol-Ms. I hope it won't get to the point when MIRVing them will be seen as the right thing to do. Assuming everything else goes as planned, this means that Russia will have about 1200 warheads. Not that much different from 1800.

To Jon Grams on single-warhead R-36M2: It's a good question, but I've never seen data on the number of deployed single-warhead R-36M2 missiles.

Thanks Pavel, I really wondered what Ivan wrote. Do you see any realistic chance that Russia could develop a brand new liquid fuel ICBM in 2016? It seems that all the liquid fuel ICBMs will be retired by then!

This is what NPOmash people are pushing for - a new liquid-fuel missile. It doesn't really have to be a new missile - an old SS-19 design will do very well (if not better, because it's been proven already). But the real question is, why would Russia need a new missile?

Six warheads in a Topol-m will mean no-penaids, light shielding and small yields. Although MIRVing it will be necessary to compensate the retirement of Voevoda, three warheads seems as a more realistic option.

There are plans to have Land Based Bulava.

And I have grave doubts if the Topol-M Missile will ever be MIRV'd.

Kolokol:
I agree- in fact even with just 3 warheads, the Topol M would have to give up it's touted MARV (maneuverable) warhead capability- an indespensible capability if it actually performs as advertised. Also, dropping yield to below the current 550KT for the purpose of mirving moves the warhead closer to tactical weapon yields, not desireable when we are talking about drastically reduced strategic warhead levels.
-Jon Grams

Jon. In such a case, a liquid fuel missile will be necessary, but I very doubt about the development of this thing, at least a decade from now.
Nevertheless, there are persisting comments about two dispensers for both the Topol-m and the Bulava:
1. A dispenser with a single "shield-penetrating" warhead.
2. A dispenser with 6 (!) MIRV.
They will be faired both in the Topol-m and in the Bulava and the "optimal mix" will be chosen according to the evolving scenario, considering no just USA, but an "all-azimuth" planning.
Off-course for a payload of 1.2 tn , 6 warheads will mean light low-yield nukes.