Following the announcement of new MacBook Pro's at WWDC today, Apple has already released a software update for the Mid 2012 MacBook Pro. The update, which weighs in at 1.06GB, offers updates to a few non-specific issues:
About MacBook Pro (Mid 2012) Software Update 1.0
This update is recommended for MacBook Pro (mid 2012) models.
The update includes fixes that improve graphics stability, external display support, and USB 3 device support.