When I get it on Tuesday (ordered in from my works warehouse as my local store doesn't stock them), it will be used for mainly school work (Graphic/multimedia apps which my brother will use and of course Word/Excel/Powerpoint).
I will also be using for my CIT (ACT's version of TAFE. US Folks may see it as a technical college (maybe?)) media production course, doing video editing.
As both FCE and the iMac (20") have been brought via normal stores (FCE via Apple's online store and the iMac via my work), I might also use it for video editing/post as part of my business.