From the White House:
The Treaty does not contain any constraints on testing, development or deployment of... current or planned United States long-range conventional strike capabilities.
From the Russian foreign ministry via the Voice of Russia:
The new START Treaty, to be signed shortly, for the first time sets limits on both nuclear and non-nuclear carriers. Russia's Foreign Minister Sergei Lavrov said, as he spoke on the 'TV Centr' Television channel on Saturday, that the provision restricting carriers with non-nuclear warheads was included in the Russian-American treaty because the United States has been producing such carriers in large quantities.