Everyone should be (relatively) happy when they read eon's latest newsletter - it answers all questions brought up in this thread.

In summary - the maintenance plan is guaranteed to cover the release of v8, regardless of timing or when you first bought your v7 software, and upgrades for Infinite will be $295 whether you choose to go from 7 to 8 ($295), or from 7 to 7.5 ($295), and then 7.5 to 8 ($295). So the maintenance plan becomes and excellent deal :)

Xstream upgrades are $495