I realize it's cheaper and easier to build a web app, but it is not as convenient to me as the Mac desktop app. Things I'd like to see improved:
Web app needs more screen magnification options - 1.5x and 2x as well as full screen.
Web app needs mini screen size that plays in a corner of my display.
Web app needs less black space around the player screen.
In the web app, please don't put any more advertisements on the web page. Your logo on the web page, in bright red and white, is an advertisement.
Treat Mac web app users better. Telling people to run Safari in 32 bit mode is treating them poorly. In OS X 10.6, you can support Safari fully or just tell people to use Firefox. That would be treating them better than you are now.
Web app TV Guide needs better integration. It does not add an extra digit or "enter" when clicking on channels. My cable remote requires these things, I have this set up in my preferences, but the TV guide page does not pick up the preferences.
When signing in to web app, remember password doesn't work for me.