My Canon EF 70-200mm f/4L lens was a champ during the Tour of California. Once I got a decent camera body to stick it on, its true quality shined like a diamond. But I have a whole void for < 70mm that I need to fill. Milling about the start area in Santa Barbara as well as the post-race interviews, it simply wasn't possible to frame a lot of shots unless I wanted closeups of nose hair.
One of the longest discussions I had during the Tour of California was asking another photographer for recommendations as to which lens to get next. Two in my book ranked highly as contenders: the Canon 16-35 f/2.8L and the Canon 17-40 f/4L. The 16-35 is twice as expensive for the extra 1mm of wideness (1.6mm on my 30D), but the f/2.8 could come in handy if I start using it for mountain bike races. The 17-40 has an extra 5mm (8mm on 30D) of reach. Another plus for the 17-40 is that is much sharper at the edges than the 16-35, though this doesn't matter as much if you have a 1.6x crop factor camera (like the 30D). This photographer actually knew colleagues who turned in their 16-35s for 17-40s because of this sharpness issue (money wasn't an issue).
Canon may have settled the debate for me last week if I can locate the money:
The new Canon EF 16-35mm II is designed to improve the sharpness issues of its predecessor. Not much is known about this lens yet as I have not seen any hands on reviews. About the only complaint I see with the new specs is that it now requires an 82mm filter instead of 77mm filter, which will cost you a few extra bucks... but you should have a few extra bucks if you can afford this lens in the first place.