People are always going to be skeptical of undrafted free agents until they prove that they can sustain a high level of play for more than a game or two. Foster had the same issues as many owners were just not sold on him to start the year however he is proving those that did not believe wrong.
Sometimes players need to catch a break to show that they are more then capable of playing in the league and being a contributor to their team both in the NFL and in fantasy. Blount is more talented then many thought, he is big, powerful and has deceptive speed for a guy his size. He can out run many LB's and then will drag DB's for extra yards.
-Watch the hurdle run again. First the vision to see the hole was not going to be there, then he spins out of it with great footwork and then watch how quiclkly he gets his speed back up after the hurdle. Had he not been touched by the pursing line backer that caused him to stumble it would have been interesting to see how long it would have taken DRC (one of the fastest guys in the league) to catch him and take him down......
http://www.youtube.com/watch?v=0nsVdTvLnqQ
-Also, he has always been a TD machine (in 2008 at Oregon 137 rushing attempts for 1002 yards, 7.3 ypc with 17 tds

, he breaks tackles, but he can also make guys miss. I think the Bucs may have found a real gem here.