Cellular-news summarizes a report from The Usable Products Company on user response to the video and music player capabilities of three specific handsets (Kyocera Angel, LG Fusic & Samsung SCH-a950) on three specific US services (Amp'd, Sprint & Verizon). Verizon came out slightly ahead, although nothing to write home about.
I find this interesting, as I subscribe to Verizon VCast (on a Motorola e815). Frankly, I've just about given up using the service as there's little content that I am interested in and it's just too painfully slow.
It doesn't have to be that way. Playing with friend's 3G handsets in Singapore a few weeks ago, there were useful sites that delivered video information rapidly enough to keep one's attention.
One technical approaches is to use 3G-324 video, i.e. video over 64 kbps circuit-switched data! This has a 6-10 second delay to get connected, but then can deliver continuous video with rapid video switching and not interruptions. But that's a QoS effect that only matter during the busy hour. The real issue is user interface design.
Of course the bigger issue is wider access to 3rd party applications. When will US operators figure out that walled gardens are stifling their business?