I will tell you what, guys. I'll bring this up with the designers. Though the hearthstone is reasonable, since many of you have become used to "ghetto hearth" style travel, it may be deemed an appropriate change.
I can make no promises.
Update: Alright, all -- we're going to make the cooldown on hearthstones 30 minutes when 3.1.0 releases. Enjoy your sweet victory.
Thanks to those who provided feedback constructively.