Does Ubuntu 11.04 fully support TRIM? And what happens if it doesn't, will my SSD wear out?
Yes, but you have to enable it manually by adding the discard option to your /etc/fstab like so:
Also the purpose of TRIM is to prevent a decrease in write throughput of the drive after much use, not to prevent it from wearing out. I have been using a drive for over a year without TRIM and have yet to suffer any performance loss, so IMHO, it is much ado about nothing.