Looks like the future of Button is a bit clearer now:

http://www.crash.net/uk/en/news_view.asp?cid=1&nid=119277

After months of media speculation, and ongoing discussions between Button and the Williams team, a financial settlement has now been reached which releases Button from his contract and leaves him free to continue with BAR into 2006 alongside new signing Rubens Barrichello.

I heard that he bought himself out of the contract for 20m, to stay where he is for 50m in pay.

Guess williams are tightening the belt anyway, now having to pay for engines and loosing there main sponsor in HP, coupled to every teams cost in new R&D for the v8's. Joyful time I fear it is not in that world.