As for another "The good, the bad, the ugly" some things have changed, some still are the way they used to be .Well, after Blaze was gone the ugly corner was long time free, I guess SoA took it, but PoA is also now elsewhere (pod).
Lamest, err, largest Ally on Sieghardt is the one with the 25 Heros, just ask your friendly Hero Messenger about it...
Every political clan is at war with cata so are we. I bet noone is allied with them, cuz noone likes them (although I ask myself if it wouldnt be boring with them gone).
If ya want to apply to cata, PM LianLi ingame or here on the boards, but make sure you are 78/75 with completed noblessquest and some good equip, else ya wont be taken.
Chances of getting into cata are slim. It is great seeing unity and pegasus with the yellow tag around alot. Looks like things are going real well for you these days.
We recently added Ritual to the ally and grow quite large by now, yeah :)
So we noticed ^^ Congrats on the growth.
As to the OP, if you want into one of the large alliances it's exactly as has been said above...As for the rest there are other less large (but not less important) alliances/clans that have a more neutral stance and less war going on, if that is whatyou are seeking.
A few I'd recommend would be Wrathofthe Just (Integrity alliance, leader there is Pameanwraith), Phanteon (leader there is Revenant). Naturally feel free to check out my own alliance via the link in my signature.