Metzen was really good when he first started at Blizzard, but the last 10 years or so his storytelling has gotten bad. If you look at the storylines across World of Warcraft and Starcraft 2 it's essentially the same. Of course the constant retcons and and non stop changing of the Warcraft lore has driven many Warcraft fans away from WoW. It was really bad a few years ago when a fan who pointed out that he had forgotten his own storyline concerning Falstad not to mention how he messed up the Eredar storyline. My personal opinion is this was more of a "you need to retire" and he didn't have much choice, especially with yet another baddie who had been previously defeated showing up yet again.
I hope they give the story responsibilities to Samwise. I think he could really turn things around and maybe inject some new life back into WoW.