The rumor is that Eldar will be one of the first cabs off the rank for a new 'dex, but how do people think 6th will affect our current book. Seen lots of references to how much Dire Avengers will benefit from the over watch rule, especially with the Divination power to let them shoot at BS4 rather than BS1.

Beyond that?

The option to take some nasty Dark Eldar melee squads appeals. Or, for that matter, a Wolf Lord, Grey Hunters etc.

Beyond allies, I wonder whether Swooping Hawks might become more useful - I'm guessing their "Intercept" power will give them "Skyfire" and let them be more effective against flyers?

The ability to kill vehicles with repeated glances, and our volume of str 6 firepower is nice as well.

Fleet's effects assaulting is nice - potential for greater fun n games with Banshees vs PA targets?

Im waiting till the book - and FAQs are out before thinking too much on composition

I don't really like the idea of the Allies rules myself, I think it'll lead to too much mix'n'matching. If I wanted Marines I'd be playing a Marine army...

That said, I'll wait and see how everything pans out before making any decisions. I can see tournaments not allowing Allies anyway, and you can already include Allies in friendly matches as it is, so it won't be much of a change if that's the case.

Ok, and beyond allies. The Eldar list itself?

A lot of Banshees will start carrying axes