Yea I would be getting rid of walker and possibly Wayne. I already have Mason and I'm keeping him strong...but I have my doubts with Coles...it just doesnt seem hes going to breakout. I would also sell Dunn high right now.
I think Brooks could be a sell-high player. Stecker, definitely, in a league where starting RBs are falling more than Darth Vader's admirals in Empire Strikes Back.
Buy low would be maybe Trent Green who is bound to kick it up and Rudi Johnson (my brother actually had both these players in a trade. He traded away Hass (another buy low), Johnson and Lelie for Trent and the two Vikes RBs. Guess that's why he's always near the bottom of the league every year.).
Peerless Price is about as low as you can get right now...although I'm not certain yet if he's going to rebound. Still you can get him cheap for sure as other owners are panicking.
Also for that matter, Vick. I'm not sure if he's thrown for over 150 yards yet. I would also keep an eye out for someone worried about Quentin Griffin.
On the high side, I'd still go with Walker and Wayne (especially since Calico is coming back). For RBs I'd check out Curtis Martin who is certainly overproducing and maybe Tiki Barber. For QBs I would seriously consider McNabb to get a good second tier QB and a decent #2 WR or RB if possible.