LOL ... man you're hysterical!
You do realize that Bruggeman was just a 1st year starter in '08 don't you? Furthermore, while Olsen was a veteran, he wasn't exactly the most gifted athlete at OG either. If you watch Iowa's PSU game ... you see him getting completely owned by Odrick (in his defense, Odrick is REALLY good). Also, Olsen didn't play against Wisconsin and yet Greene still managed to have one of his best games of the season. That would suggest that Iowa has more than adequate talent/depth at OG.
Besides, what you quickly seem to forget is that while Iowa lost 2 guys on the OL due to graduation ... Iowa also got back 2 guys from injury from 2008. Namely, Iowa has BOTH Doering and Richardson back, both of whom are former starters prior to their respective injuries ... and both are, yet again, getting plenty of reps with the first stringers!
I will certainly admit that Iowa's play at C will probably not be quite as good with Bruggeman gone ... however, Koeppel is a guy who's seen game-reps. Furthermore, by many accounts, it sounds like he's doing a solid job too. Thus, with arguably improved play at BOTH OG and OT spots and a slight downgrade at C ... that still pretty much equates to a '09 OL that is AT LEAST as good as the '08 OL.
Jon Miller, (great guy, hawkeye homer) thinks Bruggeman was the best Hawk center in the last 10 years, if not ever. He was Miller's solid MVP of 2008 (yeah, not Greene). And Brugge really was the anchor and leader of the O-line. That's going to be alot bigger loss than Hawk fans are alluding to.........