I think there are only two guys who do most of the coding. The fact that they release any updates at all is pretty amazing.
That said, the latest release I know of is November 1st. Beta 3 Patch 8. The August release is just the straight Beta 3.
Just remember: This is Microsoft's biggest announcement in 5 years. Jobs and Apple won't want to give it to them easy.
Now's their chance to really blow people away. The more publicity they can suck away from Vista the better.