Google's $199 Nexus 7 tablet isn't on sale yet, but if you managed to pick one up at Google I/O, you might notice that an over-the-air software update is hitting your slate right now. We don't have a changelog for the 12.6MB update, and Google's description doesn't really help. As far as we can tell, it's identical to one the company used on the previous OTA build. One change is plainly evident when you reboot the device, though: the Google Wallet app is now preloaded, which could help you make NFC mobile payments on the go. It doesn't seem like Google's potentially infringing universal search bar has been changed in this build: it pulled up apps and contacts as well as web search possibilities when we tested it out. We also noticed that the update goes through a process of "optimizing apps" when you first install the build.
Update: Google tells us that this update just brings the Google I/O version of the Nexus 7 up to date with the rest of the Android 4.1 Jelly Bean rollout, and that there might be some performance tweaks as well.