Russia is undertaking what appears to be a major modernization of its Tu-160 fleet. In addition to building new bombers of this type, the Kazan Aviation Plant is upgrading some old ones - according to Gen. Anatoli Zhikharev, deputy commander of the 37th Air Army, they sent one Tu-160 aircraft to Kazan in 2007 and two - in the first few months of 2008. Zhikharev also said that one of these aircraft is expected to return to service in 2008.
It appears that the modernization includes upgrade of avionics that would allow the bombers to fly conventional missions (see also here). The plan is to perform upgrades at a rate of 2-3 aircraft a year.