I went to Bletchly this summer and saw the rebuilt Colossus. It's pretty much as awesome as it seems - they even have some vacume tubes from the origional machines (or...from the same time as the origional? I don't recall).

In any case, at the time they had a version of the code breaking system runnin on a laptop (I think it was an older powerbook) and the Colossus, once it had warmed up, kicked the laptop's ass.

I think it'll be an interesting contest.