Hello, bikes can go 25-30 mph, no problem.
*Bikers* can't always do that, though. There are a lot of recreational riders around here - especially on the weekends - and they usually don't have a problem with keeping up with traffic. Of course, they're not the ones making LH turns across 7 lanes of traffic at 7:55am, either. They stick to the less traveled roads (bike routes + paths, especially), obey the laws, and generally "ride smart".
No, the problem that I have is the college kid that thinks he owns the road and that everyone should wait for *him* because, dammit, that's the law! (I work near a college, see this all the time and routinely am amazed that no one has been killed yet).
Or the half-dozen executives that ride to work once a month to prove how "green" they are, and do the aforementioned 10-12 mph in the fast lane because they can't make their legs go any faster....
The folks who ride everyday - looks like there's some on this thread - would be pretty sensible, I'd imagine. As usual, it's the bad apples that spoil the whole bunch.