Just to get it out the way first; yes there's some issues at the moment with this game. It's an MMO, and a big one at that, and to be frank I expected it to be in a far worse state than this. Perhaps I've been lucky, but it's not crashed at all for me. In fact, personally I haven't had any difficulties at all so far on my way to level 30.
What problems I know of have been ones I've read about on the forums, and there are quite a few. However, Funcom are working flat out fixing things, with patches and corrections going on every day or so, and problems are being fixed fast.
I've also read some complaints about the "high system requirements", but if I may be brutally honest, that's just stupid. It's a brand new game with very impressive graphics, and enormous play areas. It looks stunning, and yet on my machine, which was high end more than a year ago (and hence upper mid-range now), I can still ramp all the graphics sliders up to maximum and it stays at a playable framerate. So to those of you moaning that World of Warcraft doesn't need such a powerful PC, I say OF COURSE IT DOESN'T; it's game engine is over three years old for goodness' sake! Progress means extra oomph requirements; live with it.
Anyway, bile vented (messy!), to the game. It keeps hold of many of the accepted systems of MMORPGs, so systems such as abilities, action keys, feats, and many of the shortcut keys will be familiar to WoW and EQ2 players (among others). This makes sense, as many players coming to the game can get on with appreciating what is new rather than needing to re-learn systems unnecessarily.
But it's the differences that make Age of Conan interesting. The combat system is far more direct than other MMOs, with three keys directly controlling left, right, and frontal attacks. Initially this seems excessively simple, with you simply choosing the angle of attack based on where the opponent's defenses are concentrated (in a visible aura surround thier character). However, advances in level bring combos, which take the form of triggerable abilities that ask you to press attack keys in an appropriate order to pull them off. Initially used as "special attacks" to complement you mundane assaults, these quickly become the only way to fight if you want to survive. This is an elegant system, as the complexity grows along with your character, allowing you to get familiar with the basic game mechanics before throwing you into the combative deep end.
The graphics are beautiful, wlthough I was disappointed with the skin textures on the main avatars, but that's a very minor quibble when the landscape you're running through looks so lovely.
The combat looks brutal, with great gouts off blood sluicing off your blade as you slice your foes open, and occasionally a particularly vicious "fatality" triggering, resulting in limbs and heads flying off in wonderfully gory detail.
Most importantly however, this game has a gritty, dirty, believable atmosphere which most fantasy games lack. It's dark, violent, centred almost entirely on human characters, and suffused with a grim humour that permeates every aspect of the game's presentation.
So in summary, the problems are all fixable and, seem mostly centred around the later game, so only the rushers are likely to hit most of them before they are fixed. For me, the more human feel of this game sets it apart from anything else out there at the moment. It's not a game to replace Warcraft or Everquest or City of Heroes. It's one to play in addition. I believe that's what the creators, who clearly adore the Conan lore, intended, and I think it was the right way to go.
I hope my thoughts have been helpful.