280 carry with a 105 is stretching the limits of what is possible. 280 total distance is more doable. But even like 265 avg carry is enough to survive on the PGA tour. You get 10-20 yards of roll and your good to go. If you look at the PGA stats there are a couple guys down around 105 averages (David Toms made 1.6 million with the slowest speed on tour) with a 262 carry (probably some combo of driver and fairway woods) that have done ok.
He posted some numbers a while back: http://thedanplan.com/blog/?p=1240 . He claims a 100-105 mph swing speed (along with a 1.5 smash factor) and 275 yard drives and with 200 yard 4 irons. That is plenty of distance to get his handicap down but you would need a killer short game and long iron accuracy to survive on tour with it. And I am always suspect in comparing pro swing speeds to amateurs. I have a feeling a lot of the pros have another 5-10mph that they don't use (44" driver instead of 46, swinging more controlled, heavier versus lighter shaft) while a guy like Dan(and me when I go to dicks) is swinging away with the lightest, longest driver as hard as they can.
I'd be interested in seeing his numbers too. I just had a lesson with Dana last week and he mentioned there is a guy on tour who has a 104mph swing, but his numbers are all optimized and he is regularly carrying the driver 280 (I can't remember his name - maybe Mvmac knows who Dana was talking about??). Anyway, 280 carry is plenty of length off the tee (carry) to be effective on tour. The problem though as you stated... Is clubhead speed for the majority of golfers. Most guys don't have optimal numbers. So they have to make up for those inefficiencies by swinging the club faster to get similar launch/carry/spin numbers.