Having played Hearthstone's beta for a while now, it made me realize how there the different classes too need to make a careful selection of which abilities (spells) etc. they wish to put in their deck.
With the constant talk of ability bloat and just having too many skills on your toolbars everywhere: "Do you think it would be an interesting or fun idea to change the gameplay of WoW in such a manner that you'd have to make a careful selection of a limited number of skills instead of having them all available at all times?"
I personally think this could be a very fun gameplay concept. Say for example limit the number of abilities you can use at any given time to 10. So you'll have to think wether or not you'll want to have sprint on your keybar or a stun instead. It would in turn again make DPS output compete with functionality, say for example that as a PvP mage you might not want to have your maximum DPS rotation skills on your toolbar, but are happy with a bit less damage output and extra CC instead.
It seems to me one of the more pleasant solutions instead of having to remove abilities from the game. And reducing the ability bloat, to me, seems like a necessity since I know many casual players who complain about how full their keybars are, or many even about basic DPS rotations having become too complex and involving too many different abilities.