Someone asked me yesterday: "what does it matter if Jim Neal and Cal Cunningham have low early name recognition? So did Kay Hagan."
That's absolutely true. Hagan's success showed that with the right amount of money you can turn a relatively unknown elected official into a US Senator in the matter of a year. That said, the less well known someone is, the more expensive it is to create a positive image of them with the electorate. That's why, generally speaking, you want to get your most well known and popular possible candidate into the race ala Robin Carnahan in Missouri for next year, or Mark Warner in Virginia last year. Warner, in particular, was such a dynamo that it freed the DSCC up to spend money in other places.
There's no doubt for Democrats in North Carolina that person is Roy Cooper, who already has 44% positive name recognition. If he doesn't run the party will still more than likely have a strong contender- but if you can get your best prospect, why bother with anyone else? It would take a lot more work and resources to turn Neal or Cunningham into a top tier challenge to Richard Burr than it would take Cooper or even Heath Shuler, who would have a strong ability to self fund.
It will be interesting if Shuler ends up being the guy though to see if there is a well funded progressive challenge to him in the primary.