Update: Forum member Frenzytom posted this today regarding the Palm Beta Test:

Top description or codename when you sign into the beta test is "Zeppelin"...which is the codename for the 800w.

Forum member scottymomo has received an email from Palm looking for Beta Testers for a new product. The email says in part:

Palm is seeking people to test an innovative new product. This product is focused on seasoned business professionals. People who commute and spend a ton of time working on email and on the phone. This test is for people looking for cutting edge technology and demand constant communication.

Qualified candidates should work in an enterprise level business and have a lot of experience with varied technologies. These people should invest a significant amount of money in their technology and use it daily.

We've long known that Palm intends to release an "enterprise" Treo this summer, as confirmed by Ed Colligan himself during their last conference call. Many expect this device to be the Treo 800w that we have seen leaked many times on our forums.

The most interesting aspect, though, is that the email suggests the following requirements: Sprint, Bluetooth user, and WiFi Access. Sounds like the rumored specs of the Treo 800w are spot-on.