I went to a local tourney last weekend, and wandered around to look at the different armies on display, and was pleased with what I saw.
One obvious thing that I noticed was that no two armies were the same. The combination of 6th edition rules leveling the playing field, and the inclusion of allies resulted in some uncharacterful, yet unique armies.
Necrons won the day, with their multiple fliers, but didn't dominate the top placings. A land raider heavy grey knghts list and an ulthwe eldar list were both in the top three with the crons.
While a small part of my fluff gland died at some of the allies combinations, overall it was exciting to see things mixed up to such a state that no two armies were alike. If you draw a grey knight opponent it could be anything, whereas once it was probably one of two or three builds.
The thing I am looking forward to seeing more is a heavier use of "count as," where allied models are painted the same as the parent army for more co-ordinated appearance.
I'm still optimistic about 6th edition, and am looking forward to getting my hellblades painted up and causing mayhem.