The gents over at the 40K Warcasting podcast have done a nice show on Warhammer 40K 5th Edition (Webisode #6). They go over the rules and what is new from 4th Edition. Skip ahead 9min to get right to the review. At the 1hr 15min mark they go over the impact of 5th Edition rules on the various armies.
Also see, The D6 Generation 5th Edition show.