At least two top manufacturers at Cebit have said that they don't have any ongoing activities when it comes to Ion and that the GN40 chipset from Intel should meet their needs. Some of them are using Silvertgorn based US15W chipset that can play basic HD, at least to 720p.
We are talking about two top Taiwanese companies who are very famous for their netbooks, or should we call them Winds and Eee PCs of the world.
The main reason might be Intel, and the fact that you don't want to do much gaming on a 10-inch screen anyway. The fear is that loosing Intel's love in 2009 might be particularly nasty divorce.
An alternative is that people who should know things don’t know about some super secretive development projects, and that small teams are indeed doing Ion behind very secretive closed doors, but this is one big if.