With 7th Edition being released tomorrow (or tonight, really), I wrote up an article for Torrent of Fire taking a look back at 6th Edition and how various armies fared. The long and short of it is that Eldar and Tau dominated while Chaos Space Marines and Dark Angels struggled. Space Marines began coming on strong at the end of 6th edition, and had a huge player base, being the most played army since their release last fall.
As a stat junkie, I am curious how the matchups and numbers will shift under the new rules set. I am sure they will, as from many indications Tau have taken a hit while Daemons and Eldar probably remain strong. Perceived boosts to Grey Knights could make them contenders again.
Anyway, check out the full article and stay tuned for more 7th Edition Updates.