I'm still trying to figure out exactly how this works, but the following information is correct:
1. Queue for a battleground from anywhere
2. Join battleground and die
3. Alt+F4 and don't log in for 3 minutes
4. Log back in, dead in Dalaran with corpse 30 yards from graveyard
I need to test this some more (does it always port you to Dalaran if you leave in a BG dead or is just because my hearth is set there?) but if your hearth is set in Dalaran this is a sure way to get there pretty quickly.