Think about it. An application that makes it easy to create games for everything from a PC to a Mac to an iPhone to a Wii. And uses Javascript - one of the most used programming languages on the planet - as it's scripting engine.
The interface is awesome, the engine is fast and flexible, and if you are an indie game developer it's very affordable.
I would venture to say that 2008 may be a good year for Unity, but I think more likely the "inflection point" will hit some time in early 2009 and you'll see some really amazing things from folks that build with this.
If you are frustrated with Adobe with its Flash and Director stuffage - give Unity3D a try and see for yourself.
I'm seriously tempted to buy a copy if only to enhance my skills as a javascript developer.