He is Tiki Barber once Brandon Jacobs came to the Giants. He is going probably 2000 total yards a season, but have between 5 and 8 touchdowns.
He's got 1 after 6 games ... he's on pace for 2 or 3 for the season.
I'd be thrilled for 5-8 tds but right now he's just a little better than useless ... maybe Kendall Wright from last year
Out of curiosity, I looked up every season since 2002 where:
(1) a running back produced 600+ yards from scrimmage over the first six weeks of the season while
(2) scoring 2 or fewer total touchdowns and
(3) the running back finished the season with 14+ games played (to clear out the injury guys)
These filters gave me 15 names plus Bell himself. Over the rest of the season, the other 15 backs averaged 7.5 touchdowns.
The worst-case comp for Bell would be 2011 Matt Forte or 2005 Warrick Dunn, who both produced just two touchdowns the rest of the way. On the other end of the spectrum, 2012 Marshawn Lynch (10), 2012 Adrian Peterson (11), 2006 Steven Jackson (14), and 2003 LaDainian Tomlinson (15) all averaged 1+ touchdown per game over the rest of the season after scoring just twice in the first six weeks.
In short... regression to the mean is a real thing.