The store at Wild Hollow has gone, but the one at Celebration remains.
I recently started a new job, which includes some occasional SL work, but which doesn't leave much time for game development. Although as part of it I have been looking more closely at other Virtual World platforms; of which the SL clones seem most promising at this point. Once you've replaced the default physics engine in OpenSim, it seems to work fairly well; while RealXtend looks good, but its graphics rendering causes problems with my work and home PCs.
Expect to see some OpenSim-based game update coming soon.