Given Peter's requirements, a real WMC extender wouldn't be suitable because they require an WMC installation. He mentioned XP machines and didn't say anything about WMC being installed. Also, I'm not certain that all WMC extenders are compatible with all versions of WMC. Not to mention they certainly don't play back nearly the number of video formats of the other boxes mentioned. Lastly, I'm not certain of who's still making real WMC extenders.

These boxes are small because they use a SoC that integrates nearly everything you need.

Also, WD have a couple of other boxes, but only the "Live" box has networking. I might have forgotten to mention that the WD box also does have standard-def support via its AV-out and component ports.

The issue I have with the CinemaTube is that it looks like it's somewhat of a no-name product. That is, a quick Chinese OEM job without much of a custom interface. You can see on its product page that the file listings etc. are contained in a rectangle mimicking something similar to an open/save dialog. I wouldn't be confident this product would receive the updates that the WD products do. I will however give them credit for showcasing the UI of their product so prominently. By comparison, take a look at the Popcorn Hour, Viewsonic or some other web sites sometime. They have what I call "crap-all" consumer data on their site. Nothing that would make most normal people even consider buying. No pictures no sale. No pictures usually means they're hiding something.