I just begain looking into Aion.  I play mmos for grouping and Dungeons :

1) Lots of Dungeons ?

2) Fun ?

3 ) Deep ?

4 Easy to find groups ?

Aion is a very good game. The graphics are beautiful and progression is easy at the start so you don't end feeling lost at the beginning. There are plenty of quests to keep you busy and your first entry into instance dungeons comes with haramel a solo dungeon avaiable at 17 if memory serves me right. The next regular dungeon you will run often is ntc as a group at mid 20's followed by fire temple from 28ish. Fire temple is a popular dungeon and easy to find groups to run it. The game does become very gear orientated at later levels especially if you pvp but for pve it's not so important... But that can be said for all mmo's. Give it a shot i bought my copy from amazon and it has filled my needs for the last 6 months.....not bad for 5 quid.