Just got my RPI2 in the mail today. I'm having the same crashing issue.
Installed using Noobs first. Had usb keyboard, mouse, and usb wifi adapter.
It started out by crashing every time I would run startx. I removed the wifi adapter and it seemed to help. However, adding the Raspberry Pi camera caused it to start again. After several reboots, it would randomly panic shortly after boot. I've also reinserted my card over 20 times as someone else mentioned.
Reloading the card with the actual Raspbian image 2015-01-31-Raspbian. Taking forever. Ugh. Will mess with it in the morning.
RPi B rev 1 - running Apache/MRTG - http://codycrew.net/mrtg (Network utilization, temperature probes)
RPi B rev 2 - for experimenting
RPi B+ - for experimenting
RPi2 - Security Camera using RPI noIR camera and motion