Word in the corporate sector is that Microsoft is planning to use Visio as its test "subscription-purchased, server-based"
application. Basically you'd pay a monthly or yearly
subscription on order to use the product which will not run on your
machine but remotely on a large
server. Thie would allow the application to be used from other
Microsoft-pushed products such as WebTV.
I know this because I worked for a company through which microsoft was looking to buy hardware to set up the necessary infrastructure.