From an end-user perspective, users can log in to their corporate network from, for example, an airport kiosk, see all of the applications they would see everyday at work, including Outlook email and any internal applications, and access them from the kiosk in a secure environment. To the user, the application would appear as if it was installed and running on their computer (seamless desktop integration), whereas in reality, the application is running on XenApp, usually hosted in their corporate environment.
An early version is shown here:
Citrix says there's still a lot of work to do but that they will be "crafting a user experience that provides a natural, transparent and effortless user interface".
At first glance, it may appear similar in functionality to existing VNC clients for the iPhone, but Citrix's XenApp apparently transmits window display information rather than the raw graphics. In that way, it's more similar to X11. In doing so, performance should be much better than VNC over network connections such as 3G and WiFi.
CNBC believes that this will remove another hurdle for the adoption of the iPhone in enterprise.