If this MobileMe upgrade came without much fanfare, that's likely because the improvements themselves just aren't that fanfarish. Highlights include new settings for public iDisk files, a revamped Web interface, and more granular privacy controls for what others can and can't do with files stored in the online repository.
The occasionally-indispensible Find My iPhone feature also received some token upgrades--more prominence in the me.com toolbar, and its own .
Saving the best for last, Apple also included one real live bug fix in the MoblieMe upgrades: an issue where exporting multiple contacts at once would fail is reportedly corrected.
So, MobileMe enthusiasts who like upgrades and hate major changes, this one's for you.