On Tuesdays we usually get new software for the grid. On Wednesday new software arrives on the Release Candidate areas of the grid. The big feature for the main grid is TMalloc, which is about memory allocation and providing information to Linden Lab (LL) for debugging the software. I think this may also provide some improvement for region crossings.
It looks like we are getting caught up on fixes and will start to see new or improved features coming out. Most of these features are still in the line of problem solving, but will do things in new ways, hopefully reducing lag and other problems.