It depends on the price you are getting right now. Lets say your average ticket price for your particular route is $250. Right now you are getting a web fare of $200. I'd say it's good and to go for it. But if the web fare is, lets say, $230 or higher, then I'd wait and see what happens. If the fare is under $200, then I'd book it for sure unless your average price is under $200 to begin with. Fares under $200 are becomming more rare, especially for flights over 2 hours long.
If you are getting a decent fare now, and decide to wait, you run the rist of the fares going higher (and that could happen as fuel prices keep going up) OR the flights selling out all together, in which case you're going nowhere fast.
The only exception to all of this is if you're flying over Thanksgiving. In that case BOOK IT NOW NOW NOW NOW NOW! And I mean NOW because it will not be there later!
Happy hunting!