Scott speed will be driving the Red Bull test car at montreal and indy. first american since andretti in 93.

If he's serious about staying with F1 then he just needs to wait for DC to retire really, and as much as i like and respect DC i think his time in F1 is coming to an end very quickly.
Lets face it though Andretti just didnt seem to be able to drive an F1 car to its full potential anyway, poor timing or not. An interesting rumor going round is that Red bull are looking to sign Rubens Barrichello. I can say with almost certainty that it wont happen. Ferrari are highly unlikely to let him go as he is one of the best drivers on the grid, certainly one of the nicest which is something the team needs considering Schumi is very isolated from the media. And Rubens is more than happy at Ferrari, lets face who wouldn't be, he may not get along with schumi but for the millions a year he's getting i am sure he doesnt mind to much:)