Attunement

I'm a fan of it.

I thought it was good back in the days of Kara, since it showed effort had been put in to be even allowed access to the content.

And I like the way it's been semi-re-introduced (not a real word, I know) with the new ICC heroics.

If you want to be able to complete the higher level content, then I feel that you should have to work for it.

It doesn't have to be a blanket-ban on everything. But simple things such as a keys are fine.
E.g. if you had to complete the ICC heroic trilogy to attune for the ICC raid. It makes a lot of sense, adds to the lore, provides much-needed gear, and it's a reasonable difficulty level.
If you can't master the tactics for the heroics, then you're going to wipe miserably in the raid anyway.

When they removed the attunement for Karazahn, it opened the door to all the moaners and whiners who felt they 'should' have raid-spots because they were level 80's too.
At least the attunement process meant that anyone entering Kara had an idea of the level of difficulty to expect, and had already acquired at least 'some' team-play experience after 80 levels of solo'ing.

And (another pet hate of mine) it meant the PvP kiddies had to learn to play PvE style before they could come and ruin things for everyone else.

More wasted content

Anyone who's read my blog, or known me, for a while, probably knows how I feel about wasted content.
I'd love to see the old instances re-vamped and brought back to heroic level.

Lots of time and effort has gone in to producing some of the most beautiful dungeons and instances ever seen in a game. And these days they are mostly wasted.

Blizz obviously listen to every word I say, since they're now planning to upgrade some of the 'classic' dungeons like the DeadMines when Cataclysm comes along.
However, what about all the rest of the stuff that's being wasted?

I popped over to Outland the other day, for a quick look around. 'Deserted' was not the word for it.
Any minute I was expecting to see a mushroom cloud or a giant crater explaining where all the people went.

Outland had plenty of heroic instances to. And some of them were a lot of fun.
I think Blizz should ditch the plan to simply upgrade a select-few of the classic dungeons and go for a game-wide change to all heroic encounters.

Once you select 'Heroic mode' from that drop down menu, all the dungeons should be at the difficulty of whatever the current level-cap is.
Sure, some would be harder than others, and some might need the odd tweak to make them even more difficult. But imagine the possibilities:

WotLK has a good number of Heroics, and the list is growing, so theirs a fair bit of choice.
But imagine if you had every single instance in the game to choose from, and all of them had bosses that dropped tokens. (no need to complicate things by adding extra epic drops).
The chances of getting bored would be pretty slim.

As I said, some would be easy, and some would be harder, just because of the nature of the encounters.

I can imagine heroic Deadmines being quite hard. But I can also imagine heroic Stockades being quite easy. But since you'll only be able to do it once per day, you wouldn't 'just' farm that one for your tokens.

I could quite easily see teams of Munquis running ShadowFang Keep or Hellfire Citadel again. And loving every minute of it.
With the instances spread all over the continents, it could even help balance the loads on the server. Since you wouldn't have the immense groups of people all in one place like you do at the moment.
And with the new cross-realm LFG system, finding groups to do even the most unusual of the dungeons shouldn't be too difficult. (Thumbs-up on that one Blizz).

Edit: While they're at it, why not include old raid content, like they've done with Onyxia. But tuned to be more 'hard-heroic' level than 'epic-raid'. A level 85 Karazahn would be alot of fun.