A story about Russia's working on a new heavy MIRVed ICBM is definitely not the kind of news that supporters of the New START treaty would like to land in the U.S. Senate in the middle of the treaty ratification debate. But since the story is out there it is worth taking a closer look at what's behind it.
First of all, it is hardly a news - the Rocket Forces issued a call for proposals for a new missile more than a year ago. The original idea was heavily lobbied for by the NPOMash design bureau that developed the UR-100NUTTH/SS-19 missile back in the 1970s and that seems to be eager to get back into the missile business. Naturally, NPOMash suggested that Russia needs "a new powerful liquid-fuel missile, with a launch mass of about 100 tonnes" - very similar to the UR-100NUTTH. It is hardly surprising that proponents of the project emphasized that the large throw-weight of the missile would allow it to carry a lot of missile defense penetration aids. Throw-weight of UR-100NUTTH is more than three times larger than that of the Topol-M/RS-24 line of solid-propellant missiles. Also, UR-100NUTTH-class missile would be able to carry the "magic" hypersonic maneuverable warhead, which was also billed as an answer to the U.S. missile defense plans (it was tested with it back in 2004).
Second, it should be noted that despite the lobbying, the project was not universally supported. The Moscow Institute of Thermal Technology (MITT), which produces Topol-Ms, argued that there is not much future in liquid-fueled missiles and that its Topol-Ms (single-warhead and MIRVed) are completely adequate, missile defense or not.
As far as I understand, after some internal discussion the Ministry of Defense announced a call for proposals for a new heavy missile without specifying that it has to be a liquid-fuel missile. Although the announcement suggested that the missile will be ready for deployment in 2016, this timeline is definitely not realistic. In fact, it is not clear if the project will be approved at all - even if we assume that Russia might need a MIRVed missile (which it doesn't), the heavy R-36M2/SS-18 could be it - the Rocket Forces just announced that they will try keep it in service until 2026.
If the New START treaty enters into force, the idea of building a new ICBM would probably be quietly buried as making little sense. But if the treaty fails in the U.S. Senate, we would probably see it going forward in some shape or form. It would still make no sense, of course, but its proponents would have a chance to argue again that Russia needs something "to counter U.S. missile defense." Not to mention that without New START there will be no need to reduce the number of missiles and warheads.
This is of course, just one of the many reasons why New START should be ratified. But I believe it is an important reason - nobody, Russia included, needs a new heavy MIRVed ICBM.