Another six months past, and now the awesome team at Canonical have another version of Ubuntu out the door. Precise is the only word I can think of to describe it; it's definitely the best version yet. As such, all System76 users are clear to upgrade immediately.
Fresh installations may proceed at will. Online upgrades are looking good too, though as always, we recommend waiting a week or two for the servers to cool down to ensure a reliable upgrade.
Current and future versions of the System76 Driver (version 2.7.3 and up) are fully compatible with 12.04 LTS.
Nevertheless, we'd recommend backing up data in any case, just in case. It's always better to be safe.
Full upgrade instructions are available here
As an added bonus, all System76 Laptops with Fingerprint Readers are now able to use the reader for authentication.