Losman did ok for the Bills, but he is merely a stop gap. The Bills need Edwards back for a strong postseason run. Hopefully he recovers quickly. The Bills have a good, young nucleus on offense with Edwards, Lynch, Evans, and Hardy (eventually). The Bills finished the season strong last year: looks like they are picking up where they left off.
Injuries did them in last season too, so let's hope this isn't too big of a problem. Their bye week came at the right time.
If I had to guess, I'd say he will be ok for the rest of the season. Or at least, the article implies that with several players saying they think he'll play against San Diego