Colston, Horn, and Henderson should all be very valuable, as well as Roy Williams (He'll get double digit looks every week from here out) and DJax. There are others too, I'm sure, I just don't feel like looking.
Of those mentioned, I do think the Saints trio will be nice, but with Horn and Colston dealing with slight injury concerns I think there is a decent chance that the same WR doesn't tear it up 3 weeks in a row. Put Cincy's trio in this category as well.
I too am very high on Williams for the same reasons your were or should have been high on him coming into the year. Great WR, big target and red zone threat and in a passing offense. For touchdowns, receptions and yards Williams should produce.
I don't think you can rule out Berrian either. A possible game in the snow might be cause for concern though.
Jennings is getting too involved for me to pick Driver although he is a WR I'd want on my team-same goes for Jennings and Favre. I'd put Glenn and Owens into this category as well.
A wildcard is Fitz. Sure he and Boldin could share in the wealth, but the team throws enough to support both and Fitz is a better red zone guy. 8+ receptions 100+ yards and a TD are not a stretch for Fitz in every game. Leinart is improving and the offense is starting to score more points. If that continues, Fitz might carry you through to the cash.
One sleeper I like (not expecting #1 numbers, though) but as a possible impact player for your flex option is Arnaz Battle. Everyone knows the 49ers are running the ball and will be stacking the line to stop Gore. Smith hasn't been bad throwing the ball and Battle is getting more looks and catches than earlier this season.
I always feel that for the most part, if you have a really good wr, they should perform for you when you need them, regardless of the competion, weather, etc. I would stick with the guys that got you to the playoffs.
TO and Steve Smith have great schedules. TO gets two bottom 5 Ds in points to WRs in ATL and NO, then he gets a rematch with Philly for the fantasy SB. Steve gets 2 bottom 10 Ds to WRs and the a hurt NYG team.
I have loved Santana's playoff schedule all year (Philly/NO/STL), but I don't think he's healthy enough to make an impact.