Just like GW2 ... WOW ... SWTOR ... Rift ... I'll be definitely willing to give it a try .. Especially considering it's something done by Blizzard.
If WoW is still going and I'm still playing it when Titan comes out .. I'll probably Sub for both games until I get bored of One (Or both) or perhaps continue playing both for yonks.
But It's kinda way to far in the future to really know what's going to happen.