WWDC has just kicked off for 2011, but you can get a little bit of the Apple iCloud newness right now in the form of automatic Application, Music and Book downloads.
Launch Settings on your iPhone, iPod touch or iPad, scroll down to Store and wait for the new options to load (you'll need to be connected to the internet to see them). Once you've checked them, the next time you purchase or download an app, a music track or a book, it'll automatically be pushed out to any device you've activated Automatic Downloads on. Brilliant.
Be warned though, if you activate Automatic Downloads for one Apple ID on a device and then attempt to activate another Apple ID on the same device (US and UK iTunes accounts for instance), you'll get a pop-up notification saying:
This Device Is Already Associated With an Apple ID.
If you turn on Automatic Downloads with your Apple ID, you cannot auto-download or download past purchases with a different Apple ID for 90 days.
A screenshot of said warning is past the break. You have been warned.