The new Nexus 7 seems to be having trouble with the GPS. At the moment the discussion seems to be growing on the Google support forums as well as over on the xda-developers forums. Regardless of the location of those discussions though, it seems the issues are similar for many users. Basically, the GPS will be working and tracking as expected and then suddenly stop.
Once stopped it goes into the "Searching" mode and apparently has a hard time coming back out. Some users report that a simple reboot will temporarily fix the issue, but that seems to be more a temporary fix than an actual solution. Other users have tried restoring the tablet back to original configuration and some have even gone as far as exchanging the tablet for new.
Both of those paths seems to bring back the original issue of a faulty GPS. We have yet to see an official statement from Google on the issue, however according to several reports in those forums -- they are aware and are working on a fix. The catch is that as of this time there is no estimate as to when that will arrive.
While we wait on a fix from Google, which hopefully will come sooner rather than later, another user seems to have good results using an app called GPS Test. This is a free app available by way of the Play Store. That all being said, while GPS related issues are cause for a fix, there is probably some advantage to this happening on a tablet as opposed to smartphone. At least this way it likely caused problems or fewer users.