I just read some blurb somewhere that a much higher %age of his outs than most lead off guys were from fly balls, from which whoever wrote it (perhaps somebody here?) suggested that if he shortens his swing and stops popping out so much, he would be likely to improve.
I still think that if he goes below .240, the Sox will send him down to the minors, whether they traded him for Carlos Lee or not. They have a fairly 'full' bench w/ plenty of guys who would be likely to at least eke out .270 or so.
That being said, I'd try to go for him if he's still there a couple of rounds after the first round of your draft.
Another guy I'm thinking who may be likely to play and steal and be a very cheap draft pick might be Endy Chavez. There's some threads on him floating around, including one where it was at least suggested that, instead of being the 'backup' as he's listed in Yahoo's depth chart, it is going to be Sledge and Johnson competing for the playing time (w/ Wilkerson, Guillen and Chavez playing somewhere...) and that Chavez should be the starter unless he totally screws up in spring training. Looking at his #s, he could perhaps grab at least 30 SB if he's full time, maybe a bit more if the Nationals are a bit more competitive this year, w/o the frequent flyer miles. Which is OK from the last round or so...