I dont know what kind of offense Chip is going to run there. But if he sticks with the same philosophies and the same offense that he used at Oregon then being a good blocker is the most important skill a wr has. Chip values that over speed, catching ability and route running. If you don't block as a WR, you won't see the field, period.
I'm curious to see how DeShaun Jackson and Jeremy Maclin enjoy that aspect of Chip Kelly. (Of course, there's a very good chance that he does things differently in the NFL).