Comment by gbl08ma

From what I know, for the 2012 Nexus 7 at least, there are lots of custom ROMs, some of them without Google Apps. There are even alternative operating systems like Ubuntu Touch. I don't know if other emerging mobile OS such as Firefox OS and Sailfish have been ported already or not, but if not, I'm sure they will, given the market share of the device and the amount of people interested. Ultimately, you can also run GNU/Linux with the usual light desktop environments.