If Jamal Lewis only had 3 yards per carry running behind Jonathan Ogden and the rest of Baltimore's talented o-line, how the hell will he get 4+ ypc or 1400 yards in Cleveland? Thomas will be awesome but he hasn't even played a game yet, and it takes a couple years to adjust sometimes. Look at Robert Gallery, he still hasn't picked it all up yet in Oakland. Not to mention the rest of Cleveland's line isn't exactly made up of Pro Bowlers.
Bottom line is that Lewis has bad knees and is getting old and is basically slow as shit compared to other backs. He isn't the playmaker he once was and he won't have many carries of 20+ yards. He has good power and will be a nice "change of pace" back, but he will split time with Jerome Harrison and possibly that Wright guy. If Droughns can rush for 1500 in Denver and come to Cleveland and only get half that, how do you expect Lewis to dramatically improve over last year's performance for the Ravens?
If Lewis stays healthy, and thats a big IF, and IF Cleveland's line does a decent job blocking, I could see Lewis possibly getting 1,000 yards.