Well when i was attacking mobs with my 70 frost mage... i would simply spam frostbolt...
nova when they got in close,
get a bit range, and frost bolt again..
so its only a couple of keys.
nothing active about it
Well it depends how you play really. If you're just fighting non elite mobs your level you could throw up frost armour, your ice barrier, scoop 5-6 mobs, hit them with a cone of cold, arcane explosion once or twice then frost them down. Blink to max range, cast a blizzard, cast a second one as they approach, then another cone of cold, keep distance til frost nova is ready again etc. It can be quite involving if you want it to be. Single targets you should have been looking at shatter combos, wind up a frostbolt and nail them with an ice lance at the same time.
In raids it's an entirely different ball game too. Different specs depending on the encounter but you'd be looking at counterspelling, crowd controlling mobs with polymorph, spell stealing at key times. Tanking the mage in Gruul's Lair etc. Making sure you blow all your cooldowns (icy veins, arcane power, trinkets etc) at the right times.
Basically, it's not just frostbolt. It can be a lot more involving if you want it to be.
I found Age Of Conan ok but my problems arose with system performance (x2 3800, 2gb ram, 7800GT). It just performed awfully, and I had to turn the graphics down to below WoW levels just to get 10fps. That really hampered my enjoyment of the game. I struggled to get on with the interface etc but most of that will be improved over time. The main problem though, was I kept wondering what was on tele, or if any mates were off down the pub. It didn't suck me into the world the way warcraft did\does.
They're both good games, and AoC will improve a lot with time but I just prefer WoW, by some margin too.