Quite sad for Barrichello as he drives into oblivion with Williams next year that his one true chance to win the championship has passed him by.
On the other hand, happy for Jenson that he took his one and only chance to take the title.
With relative stability in the regulations over the winter Brawn will struggle to match the development pace of Ferrari, McLaren and Red Bull - all of which have caught up Brawn's performance since the start of the season even with a testing ban.
I doubt he'll feel foolish since what Dave has said makes a great deal of sense.
Although, Nick Fry (I think) did say that they have been working on the 2010 car without doing too much to the 2009 car over the last few races, which explains their comparitive lack of pace and development. I think they'll still be up there next season, whether they are WCC material again, we will wait and see.