WotLK Release Date Speculation

As so many others I will throw out my estimates for the release date of the coming addon.

Currently the beta is running, with the level cap at 77 and no content beyond that. No raids yet, Lake Wintergrasp is still not functional, most professions are not yet complete and all classes are still being worked on heavily.

I am pretty sure that most content is already finished to some degree, it just has not been put on the beta realms yet.

One can venture an educated guess by looking at the calendar. There are two events in October that may be a perfect opportunity to launch the expansion, or at least the in-game events that lead up to it.

The first is Blizzcon on October 10th and 11th. The other is Hallow's End, which starts on October 18th, and ends on November 1st.

From wowwiki.com:
Hallow's End marks the day the group of undead, who would later be known as the Forsaken, broke free of the Lich King's dominance and once again regained their free will. They celebrate this occasion by setting fire to a wickerman after a short speech from Sylvanas herself and smearing the ashes across their faces.

Blizzard CMs have stated repeatedly, that the launch of the expansion will be preceded by some kind of world event.
Now, my guess is, that this introductory event will either be a modified Hallow's End or will be tied into it in some way. Blizzcon would also be a good point to launch patch 3.0 (which most likely will come before the addon hits the shelves, same as with patch 2.0 and BC).

This would put the release of the addon itself somewhere at the end of October or the beginning of November.

Another way to get an estimate would be to look at BC. The beta for BC started in early October 2006, with the signup beginning late September. The game came out January 16th, 2007.
This puts the duration at slightly less than three and a half months. With the WotLK beta starting in early July, this would suggest mid to late October, which fits nicely.

Of course Blizzard does not have the habit of keeping hard deadlines with their projects. Their release cycle is dictated by internal technical factors, not external ones as with so many other companies (which is a Good Thing)

Still, fitting the whole story of the Lich King into existing events is too big an opportunity to let it slip by and I am pretty sure that they are trying to get it done in time for it.