The level cap bump to 75 is interesting. I have had a difficult time getting re-used to the game when I've revisited. In part because at L 60-65, the number of hotkeys is insane. I've forgotten everything.
I agree with this. This is a large problem with MMORPGs today because developers are scared shitless about the concept of taking something away from the players, even when that might lead to a better gameplay experience. D&D 4th Edition solved this problem nicely. You get powers regularly throughout your first 10 (out of 30) levels, but once you get into the tens and twenties, you have to give up old abilities to get new ones. This means that sure, your high level wizard might not be able to cast Fireball any more at higher levels, but he's got other, better abilities to replace it.
If a MMORPG used this, you could keep adding new abilities to higher levels without ever ending up cluttering the interface. Let players visit a class trainer to swap between powers they have previously learned at a nominal price so that they don't risk gimping themselves with poor choices early on.
One of the worst parts of LOTRO is getting back into it after a break. I've got 6 or so fully stacked rows of buttons in my interface, which is way too much.