Latest as of now, is 4.1.2. So there won't be any updates, at least until 4.2 but even that isn't said that Google will roll an official Nexus 7 version. But all custom ROM's here mate are all updated from official sources so no worries from being "outdated"
But if you really want to run stock, I suggest this. This will truly roll back to OTA connection. But here's the links to super stock releases from Google, on top.
Thanks! I think there must be a reasonable subset of users who want root, but aren't fussed about running a custom ROM. I know a few such, at least.