Imagine someone sues you for spilling coffee on them. They are willing to settle if you cut your hand off. You disagree, go to court, and the court awards the plaintiff twenty bucks. Same thing happens in the corporate world, too.
Honestly, Oracle's patents should be easy to find prior art for. Nothing in computer science is new, even if a patent examiner or some dude working 9-5 at Sun say they are.
BigTable is using GFS, so it will not be much use to Oracle without GFS. Also, since Google nicely described some of the major ideas behind BigTable in a paper, there are few Open-Source implementations of it. I expect that like many database systems - getting a license is easier than building and maintaining a stable system :)
Claims on slides and videos don't cut it for me anymore (I used to be borderline fanboy of Google's tech reports, like so many others.) Stonebraker has a great paper analyzing Google's claims with respect to databases (and it doesn't look so revolutionary.) That's why I'd be surprised if Oracle buys Google's hype just like that.