SC2, Zerg: What the hell is taking so long?

I went over the SC2 website and for the race information. Terran and Protoss are pretty much complete and ready to go beta. But for the Zerg they only have the bios for 3 units. They keep on adding units, removing units, and changing abilities. Like I thought from the beginning, the zerg race was pretty much perfected in sc1. I dont know what they could possibly do out shine the sc1 zerg.

But anyways, Blizzard looks like they're complete stumped and as time goes on I doubt they will be able to stall for much longer. Vivendi is probably knocking at their door wondering where their finished game is.

Anyways, what do you guys think about the zerg? And also people have said that the overall game play has slowed down in SC2. Do you believe that will drastically alter the game play?