As fans we often become too enamored with the the "style" not the substance. The fact remains proven that you can find decent RBs on other among people's Practise Squads, UDFA'S, FA's. Just look at Priest Holmes, Willie Parker, the kid from GB, Justin Vargas, etc, etc, ETC!
You also have to look at the fact that given the current rules the running game in the NFL is becoming less and less important and every year goes by. Just like we have seen the extinctiion of the FB postiion over the past decade, we have seen the running game become less of a factor in the overall offensive importance all over the NFL.
That's not to say you don't need a runninng game to succeed, you just don't need a "great" running game to win superbowls. We've done it in 2001 and 2003 and we will do it again in 2007. You don't have to be great, just effecient.
BOTTOM LINE: A great NT is one of the rarest creatures to find for NFL teams, RBs can be found all over the place. It isn't glamorous, not exciting for fans when your team keeps drafting the Seymours, Warrens, Wilfolks, Mankins of the world, while other teams draft the glamor boys like the David Terrells and Eli Mannings. However those dull draft days often lead to VERY HAPPY Sundays in the fall