I took Joost for a test drive this morning, and it looks pretty slick besides the occasional beta bugs (for instance, it isn't working with IE or Safari right now for some reason). Joost uses a local video player client that interacts with the Web to stream videos using an H.264 video codec, and there's a modified Mozilla browser built over it all so the client will work with pretty much any OS.I don't know how Joost's proprietary codec works, but I like what I've seen so far. The video streamed smoothly and the quality was very good, even at full screen resolution, and the stereo sound was clear and crisp. Channel changing did take some time, though. Channels and content are heavily weighted toward the 16-24 crowd; viral-ish stuff, pop-flavored rockumentaries, extreme sports footage, and so on.
There are also widget-like plugins, like news tickers, a clock, a rating tool for rating videos, and an IM plugin that lets you use your Google Talk or Jabber account to IM through the service. (Click here to check out the on-screen widgets). Navigation takes a bit of getting used to, as Joost has opted not to use the typical Windows navigation symbols, but give it a few minutes and you'll be fine.
There isn't a lot of content yet, but as it's still an invitation-only beta product, that's to be expected. It's hard to judge a video service separate from its content though, since a video service is only as good as the video clips it delivers. Joost has the technical prowess to satisfy the video-watching crowd that wants a better picture and sound, but whether going after original content leads to a more compelling product than one that relies on user-generated/submitted stuff remains to be seen.
Thanks to Appscout for the review. Im still waiting.... anyone got a token they want to give me?