Well, we're still working on our "elevator pitch," so to speak. But the main (brief) points that we generally try to convey are:
1. It's about as similar to Bejeweled as Bejeweled is to Tetris.
2. This is one of the more original block-based puzzle mechanics to come along since Bejeweled.
3. It's ridiculously fun, and will be packed with content and modes like you wouldn't believe, including versus support and full co-op throughout the game.
Generally less is more with this sort of thing, so I think that's pretty much the salient points, though there's a lot more that could be said. Good question!