I don't like the idea at all. I'm not averse to tkaing a position other than RB in the first and/or 2nd rounds, but intentionally going in ignoring them for the first 4 rounds just seems dumb.
...and no, you can't 'corner the market'. There's about 18-20 solid WR picks that are either solid #1's or serviceable #1 and #2 types if you get 2 of them. Taking 4 of them will still leave every other team with a chance of getting a Wayne/R Williams and that's really not so bad if you are sporting Alexander/McGahee, S Jax/Caddy, or R Brown/Edge in your backfield.
Plus those teams would probably be set at RB after your error, giving them a big advantage over you. When you are scrambling for RB in the 5th and 6th rounds and beyond, they will be getting their QB's, backup players, and 3rd WR's.