Since the Mac App Store debut I've been disappointed with the way Apple had three unique ways to update the OS, the applications on my Mac, and the applications on my iPhone and iPad.
I'm very much looking forward to Mountain Lion's consolidation of two of these. Serenity Caldwell for Macworld reports:
Software Update, possibly the slowest Apple program on your Mac, is saying goodbye in Mountain Lion. Instead, the App Store will be handling any system patches, along with updates for your Mac App Store programs. And as a bonus, Notification Center will alert you in the background when updates are available, saving you five minutes of staring at the “Checking for new software” window.
This is great. I hope Notification Center also notifies me of updates that are available in iTunes too; iPhone and iPad applications, Podcasts, episodes of my TV shows, etc.