I have been having a couple of problems with my Thunderbolt. I've had mine since September 2011.
Most recently the touchscreen has been acting very erratic. I will touch the top part of the screen and it thinks I'm touching the bottom part. Sometimes it won't take any input at all. Usually if I turn the screen off and on it will fix the issue for a few minutes, but it is getting pretty pervasive. Even a reboot only fixes it for so long.
Also, my ability to access the mobile data will randomly shut off. Sometimes I can go into settings and turn it back on, but most times a reboot is required.
Any ideas how I can resolve these?