Couple of thoughts:
1.) We've seen time and time again that NWP is too quick to switch patterns. For example, you see the pattern flipping around the 5th of the month, but it doesn't wind up changing until the 9th or 10th. I don't see that happening here. The reliable, long range modeling is showing a slow but steady progression to at least a marginally favorable pattern.
2.) It's December, and it's La Nina. These are two hostile background environments for us. Folks need to realize this won't be a 2009-2010 December and be happy with what we get.
3.) Climo say that 7% of winters here feature a White Christmas. I honestly believe that a bit of patience will yield us a higher than normal chance of a White Christmas this year.