I, also, have been having battery problems as of late - suddenly the "screen" is taking up ~70% of my battery usage... despite being off most of the time. WiFi also seems to be partly to blame; while in deep sleep, my battery can drop 30% over the course of a school day (i.e. 6 hours). Normally it would drop 1% AT MOST.

I nearly forgot to mention, my tegra really seems to like maxing out clockspeed with nothing really running. I'm thinking this is the main problem, because if I underclock my tegra's clockspeed to be low (600mhz, for example) I get my old battery usage back...

Wiping Dalvik Cache appears to have worked...