I'd like to provide an update on this situation in case anyone is in the same boat I am.
I went to the Apple store today. I asked if I could downgrade my operating system. They said no, since it came pre-installed with Lion. I asked if Final Cut Studio 3 was compatible with Lion. They said yes, for the most part. They said there was an issue exporting video in 1080p.
Of course, conveniently Apple is no longer selling FCS3 and the ones on Ebay I saw have gone up to more than $650 a copy. I am out $400 for stupidly buying FCS2 a few months ago, which is now useless to me. I told the Apple guy that I'm not buying FCS X until they work out all the kinks. This leaves me with this laptop that I bought for video editing with no editing software to use.
I never thought I'd say this, but I'm actually considering getting Premiere Pro now for Apple, which is supported in Lion and is running a deal for 50% off. (http://www.adobe.com/products/creativesuite/faq.html#lion-os) If Apple doesn't start selling FCS 3 again, they are really not giving me any choice but to switch!