Well, having been back playing WoW for a week now I thought I'd share my thoughts on the current state of play:
My Paladin, Jana (apologies for the Welfare Epics), can comfortably perform well enough in a DPS role for Heroics. I've still got to re-learn encounters, especially particular Heroic encounters, but I'm happy that I won't be letting the group down by taking her over my Warlock. Tanking is still fun in the gear I've collected. I've done a couple of normal lvl70 instance runs now and it's all pretty straightforward. Mana can be something of an issue, but that may be only because of outgearing the instance somewhat. Learning to be a little more frugal may be a good idea. Next stop, better avoidance gear and HP's and then Heroics / Raid Off-tanking I love Windfury. It can have my grotesque human-totem hybrid babies. Jana can do well enough in 10-man raids, but I still have a lot to (re-)learn...
What do I have to learn? Well, the most obvious part is the Karazhan encounters from the perspective of a melee character: keeping in the right position behind the target, getting out of range on timed AoE or area effect damaging debuffs etc. Also getting the hang of CC and using the /focus commands would be pretty handy too (yeah, we had 2 priests and no hunters on Moroes, gogo Turn Evil...). But above all what I find most difficult, and probably what separates (proverbially) the men from the boys is dealing with all the information you have coming in at any one time.
At any given time a newish player in a raid may need to make upwards of a dozen concious decisions in some short number of seconds. Those who have been raiding for some time make these decisions automatically and without thinking about it - hear the raid warning, do your special thing, get back to the fold - all the while keeping careful note of swing timers, cooldowns, and their general given roles (DPS/Tanking/Healing etc). It's this, and not the gear gap, which I think is the most significant hurdle to progressing from small group encounters to raids.
So in an effort to improve my performance I'm making a concerted effort to get to grips with custom UI's, boss mods, macro's and the like so as to streamline my decision-making processes. Just downloading and installing the mods isn't enough, you need to understand the numerous visual and auditory clues those mods provide. If a warning isn't necessary on an encounter for your role turn the damn thing off, if it's critical make sure you'll notice when you get the warning.
Now seems like a good time to put in a couple of handy blog links. So I will:
Josh over at Eye For An Eye's take on UI Mods.
Siha at Banana Shoulders, for a Holy Paladin's Take on UI's.
The UI mods available are a great addition to WoW in all areas of the game. Similarly simple action automation is a boon - it's amazing how much effort a weapon-switch or Judge+Reseal macro saves. Players need to be careful though that all the information they get on screen doesn't lead to information overload. Easing your way in, starting with non-standard Unit Frames, ActionBars and Boss Mods and then slowly working your way up towards more complex and information-rich mods such as swing timers and cooldown trackers is probably more sensible than looking at the various sites around and grabbing everything they suggest. Blogs and other informative sites suggesting mods are long-time veterans of the game and hence are well used to all the information coming at them during your typical raid. You, if you are anything like me, won't be.