I feel
any Blanket change applied to this game is wrong. The blanket method is lazy and can never effect every class and combo the same. I know it's more work to address every class/combo individually, but this game is based on that very foundation and must be treated that way ALWAYS.
If they want to put a CD on a skill fine, address that skill/skills one at a time and look at each class/combo to see where and how much to change them. The blanket Mana % was poor to say the least and was removed. this GCD looks a lot like the Mana change and seems to be reserecting the same responce from the community.
Yes each class has a large amount of skills to choose from, the issue is many of them are not functioning correctly or lack usefulness due to poor scaling at higher levels. This creates a bottleneck effect where only a handful of skills are used on each class/combo. As it is now we could put every skill available on about 3 Action Bars, but many have no real function so there is no point to even place them there.
I don't understand the previous balance attempts to the classes that have recieved it, if they had planned to implement this change and nullify the previous balance efforts. In my opinion this change is a step backwards and achieves nothing positive.
My suggestion is to look at each skill and implement changes that have at least a shred of logic to them. The GCD reverts any speed boosting effects that currently exsist in the game. The Raid and Curse runes have no use now, along with any and all speed buffs and or foods/potions. Why offer these advancement only to erase their effect? Why have speed ratings on weapons and intice players to try to reduce those limits? Just allow everyone to attack at the one second mark and no less, then replace the speed boosts with something else.
I know my suggestion of removing speed boosts is a massive task but you can't just dump this blanket speed change on the community and give nothing to balance it in some way. I feel this attempt (GCD) is much to late in the life of this game. I feel Ice Blade should have a Cast time and not be instant, but that is another subject to be discussed in a different post.
Sorry for the long post...Sheesh!!

:p