These statements confuse me. Is there a specific app that allows the streaming or did you just mean each specific app.
I've got the impression that this works as an App type of deal, and you can turn it on or off.
Basically what is going on here is the Provider is sending the 480p stream when the App is set to "On".
I also believe the App functions as an Upconverter (this is where the optimizations come in) and is another reason the 480p+ video looks so good.
I've got a Blu-Ray player that does Upconversion of DVD's - it works so well that I can't really tell the difference between Blu-Ray and DVD.
These are both going to a 52" 1080p Plasma screen, so I should be able to see differences, but I really can't.