Well, Kadaan is correct so far:
From this, my guess are:
- 3.3 will come out in December or January (4 or 5 months after 3.2)
- 4.0 will come out 14-15 months after Blizzcon (August 09 -> October/November 2010)
- There will be a 3.4 content patch with something in it around April (3-4 months after 3.3, 6-7 months before 4.0)
As 3.3 will be available next week apparently.
Another 10-11 months to go before Cataclysm it seems
I hope before that tbh.