If Blizzcon is anything like the WoW forums, you'll need a survival guide... and an impervious flame-retardant suit lined with lead.
Blizzard has written a guide for everyone attending Blizzcon: a survival guide!
Get Your Badge Early
There will be lines at the badge pick-up stations when the show first opens. Beat the rush by coming by on Thursday between 4 and 11 p.m. or on Friday starting at 7 a.m.
Make a (rough) schedule
One of the easiest and biggest pitfalls that even experienced conference-goers can make is poor time management. On one end of the spectrum is cramming everything humanly possible into a rigidly regimented schedule, and on the other end is doing one activity for too long and missing out on something else. A happy medium, where you have a defined but flexible schedule, is best. Having a list of priorities for each day can work well. Keep in mind that there are differences between Friday's and Saturday's offerings, such as the different slate of developer panels for each day.
Get to the live events early
The live events, such as the developer panels and the tournaments, were heavily attended at the first BlizzCon - since there will likely be even more people and interest this time, come early. For these live events, you can't beat the view of the action that a well-placed seat can provide.
Go learn how to survive at Blizzard's site.