- AirPlay is a relatively new feature for iOS. It is a way to "throw" media content from any mobile device to a nearby video/audio output devices.
- AirDrop is a newly announced feature coming on OSX Lion. The feature will be a seamless file sharing method, "throwing" any content between nearby devices.
Overtime, iCloud will expand in scale, scope, and capability.
On a closely related tangent, I also believe Lion will be the last iteration of "OSX". Lion is a stop gap, before the full unveiling of unified platform for our modern mobile age.
As a new mobile and integrated future dawns, OSX as a traditional immobile and autonomous platform (surrounded by fragmented devices) of the PC Age will fade into the anneals of history.
By the next major OS release, all of Apples devices are going to be rolled into one seamless experience. That's not to say iDevices and Mac's will perform the same functions. On the contrary, they will still perform vital and differentiated roles in our lives, but the paradigm division between the two will be invisible.
Today it is a common routine to bounce back and forth between PC's and mobile devices (sometimes juggling both at the same time), they are often seen as two different platforms, not complementary platforms.
Tomorrow this transition between devices will be intuitive and seamless, not only in the ability to access all your data, but just as importantly in how you access you data.
And it all began with the elegant and intuitive liberation of 1,000 songs from your computer so you could put them "in your pocket".