I second the idea of background and audio mode. Sometimes you'd like to stick your phone in your pocket and listen and now you have to do it on full screen with the app in the foreground.. both the home and the screen off buttons on my Hero result in the app shutting down.
Also, using a Classic and the guide only opens the guide on my DVR... not sure if that's why.
Otherwise, very happy.
If you guys are seeing this in a future update, you may consider posting it in this thread (https://community.sling.com/thread/2924). Since it exists in the Enhancement Request Forum, it may pull a little more weight.
The "guide" button in the Slingplayer Mobile for Andriod only brings up the respective set-top box's "guide" functionality. It's unlike the Slingplayer Desktop 2.0 where it brings up the electronic program guide content from Zap2It.