Google: PageRank Dilution Through A 301 Redirect Is A Myth
Just under three years ago, we reported that 301 redirects don’t pass full PageRank and that you should try to link through a normal link versus using 301 redirects.
The truth is, a 301 redirect and a link pass the same amount of PageRank. There is no more dilution of PageRank with a 301 redirect when compared to using a normal link.
Matt Cutts squashed this myth that I believe many SEOs thought to be true, today in a video:
The amount of PageRank that dissipates through a 301 is currently identical to the amount of PageRank that dissipates through a link.
So the myth that you should not use 301 redirects because it will dissipate more PageRank than using a normal link is not valid.