The current stable release of Blender remains 2.49b. In Second Life two of the main sculpty tools use Blender: Primstar and JASS2. Both of those still use Blender 2.49b. However, the beta versions of Blender 2.5 are becoming popular with those working with mesh in Second Life. The reason for that is the Collada Export/Import features in Blender 2.56a have more fixes. The Collada features have just been updated again and this week more work will be done on Collada.
If you are finding problems with your Second Life Mesh Imports because of Collada bugs, get over to Letwory Interactive and the Blender 2.5 Tracker and let them know.

