Rumor says that the Treo 90 would have a color screen, 16 MB memory, no wireless, and an SD slot. It appears that it will have the same form factor as a Treo 270/180.
It will be powered by a 33 Mhz processor, will weigh 4 ounces, and cost $300. It should be available with the next 2 weeks.
This looks to be true because 1) You can buy it here, 2) Looking at a google cache of Blue Nomad's website they mention it, 3) Steve Bush of Brighthand fame mentioned it in a recent article, and 4) Donna Dubinsky hinted of something like this in her last conference call.
One user of PDAbuzz said this about the future of PDA's.
"(1) Color is in, B&W is out.
(2) Thumboards are in, Graffiti is out.
(3) Industry-standard expansion is in, proprietary expansion is out.
(4) Small is in, big is out.
(5) Wireless is in for (only) those who want it and can afford it. "
The Treo 90 fits all of these criteria; hopefully we'll see it soon!