My good buddy Gus over at Citrix posted up today that the latest and greatest XenApp client package is available for beta.
These clients support Windows Vista, XP, 2003 & 2000
Citrix is looking for users to test drive the latest version of the XenApp Client. There is no need to update your XenApp Server farms to participate in this Beta. This client, due to ship with the next major release of XenApp, has been designed to work with all existing versions of Presentation Server 4.X Servers. All you need to do is upgrade your client software.
This software is still in active development and, as such, Citrix does not recommend its use in a production environment. Support for this Beta client is available only through the Citrix Support Forum.