I wonder how many abilities are used in rotations for each.
On some toons, i distinctly remember having a lot of abilities that I just never or rarely used. With my DK, especially as a tank, I use a good portion of the abilities I have on my bars – more than I ever used as a Drood. In fact, I've had to modify my key bindings to be able to hit my abilities quickly on my DK.
Definitely, your total number of abilities doesn't indicate how many abilities you actually use day to day. Especially for the top-button classes, I imagine most of them aren't used in rotations or hot keys... for instance, hunters have about 14 aspects and trackings, mages have 12 portal/teleport/refreshment spells, etc.
I was curious, because I assumed that shamans would have the most overall abilities, because of the totems (21, untalented). Of course, most totems are in a gray area - rotations wise. Ignoring totems, I use about 9 class abilities in most rotations.
I'm not surprised to see DK at the bottom. They aren't pushing any less buttons, they just aren't carrying around 4 years and 2 expansions worth of dead weight. DK's also tend to get more active abilities through talents than most other classes. (I think they can get 6 per tree, shamans get 3 or 4)
And I would certainly agree that tanking requires more at-yer-fingertips abilities than dps or healing.
If I recall correctly, tanking in bear was so EZ-mode:
Keep Faerie Fire up, Mangle when it's up, stack Lacertate (DoT) 5 times and make sure you refresh before it runs out, to keep the 5-stack, keep fingers on the AoE taunt and single-target taunt, just in case. Optional - spam Swipe if there is more than 1 target (between your Mangles and Lacerates). That's pretty much it besides a stun, charge and Frenzied-Regeneration ... and if you're using charge or regen a lot, something is probably wrong with the party.
The Death Knight definitely makes tanking more exciting and changes up your rotations with 2-3 different shields, a spammable party buffe, proc-reactive attacks, runic power dumps, 4 AoE dmg options, self-healing with attacks, 2 self-healing options with pet, at least 2 silence options, a quick refresh to your runes to make them all instantly active, and maybe a few more things. And, as a tank, you use many of them, depending on the type of fight. So, yeah ... I fumble my keys a lot more as my DK than as my Druid. It's a lot to remember. But, if you don't mess up too much, you can solo some 5-Man quests in Icecrown. ;)
I was curious, because I assumed that shamans would have the most overall abilities, because of the totems (21, untalented). Of course, most totems are in a gray area - rotations wise. Ignoring totems, I use about 9 class abilities in most rotations.
I was thinking shammies and hunters would be at the top - totems, aspects, tracking, traps. And, I guess they are, considering the Druid doesn't totally count, as you rarely have to shift from one form to the other and use many, if any, of the abilities ... even in PVP.
