Found a pleasant surprise.
The video podcast from NPR's live concerts feed at NPR: Live Concerts from All Songs Considered Podcast
would not play right on my 8820. I would get audio, but not the video track. Just black screen. There have been posts on the forum from people who had such trouble with some mp4 files.
The solution I found at the time was to download on the computer, and convert to the blackberry with media manager. But it took a long time, and we all know the problems with media manager, so I only did it the one time when I was experimenting.
Well, the pleasant surprise, the files play on the 9700 after straight download to the device from the NPR feed. Very, very cool.
I recommend the The Low Anthem performance.