Playing a mage is ... well, not as fun as I was hoping it would be. The mage quest line is as fun as it is short, if it lasted 3 times as long I'd be praising it. Plus to me, it was kind of too easy - cast a dual hand flame cloak, ice cloak, run around and enemies die. Around lvl 26 with the archmage robes, the dragon mask that gives you +100% magicka regen, a full set of 20-40% resistance boots and roughly 20k in cash, I decided this is no fun. Sure I could have increased the difficulty level, but that wouldn't really be more fun, just frustrating.
So I created yet another, at this point lvl 22 Imperial archer/soldier/assasin and it's been a blast. I might be alone on this but to me both regular combat and spellcasting suck - only archery gives me the satisfaction and makes me feel I'm actually using skill, not just button mashing.
As for DLC, from what I heard they're not going to be releasing a ton of small 9$ add-ons that will add amazing stuff like horse armor
They're planning to do something similar to what they did with Oblivion - "old school big" add ons.