I had the same issue this morning, this afternoon, I turned off the system, turned it back on and I was able to connect to the store, however, it didn't seem to work properly. I was looking for Sketchcross, a game that I bought and wanted to download but the search didn't work. When I try to look for it under games, the store just froze and wouldn't respond.
Same issue as everyone else, upgraded firmware for my 2000. I never had this issue prior to this patch and like others, the battery life is now junk. It lasts about a day in standby whereas it was literally weeks before.
As per someone's suggestion, I queued the download through the webstore and I was able to download the game, however, it seems really silly that I needed such a workaround. At this point, I wish I could roll back the firmware update and just play the games that I had with the battery life that was there before.