Dan Rayburn at StreamingMedia.com has some good tips when shopping for a higher-end video hosting provider. The target audience for the article should be organizations that are looking to do some serious video streaming. Some of the potential providers include Akamai, Limelight Networks, and VitalStream, all of whom have developed significant content delivery networks.

If you're a smaller organization looking to put a few videos on the web, I would check out Brightcove.

Two points left out of the article that I would have mentioned (but are quite obvious):
1. Determine how much disk space you will need, is available and at what cost for expansion
2. Determine the costs associated with bandwidth usage