How about actual dates?

1 week = 7/28
2 weeks = 8/4
3 weeks = 8/11
4 weeks = 8/18 (blizzcon week)
5 weeks = 8/25

I vote 2 weeks, or 5 weeks if stuff breaks. They wouldn't release it the same week as blizzcon, and probably not even the week before. So 8/4 gets my vote!