12/16/13 update: It appears that this issue is generally related to "getting busy" with the G2. One specific activity that is emerging as a repeatable observation across the G2 community is viewing videos in the browser (not via the YouTube app). This is not to say that this is a 100% prerequisite, it's just an activity that many (not all!) G2 owners report just prior to the G2 spazzing-out.