It sounds similar to the boxee box with the exception that the boxee box does a lot of streaming stuff over the net in addition to the local network and comes with built in wifi.
http://www.boxee.tv/box
WDTV live does Youtube Pandora and Flickr, and a Netflix deal is rumored to be in the works (would be enabled by a firmware update).
Personally online streaming is a non-issue for me, I got the Live for the large array of media support (including .mkv containers). A quick Google would seem to indicate that mkv is problematic for the boxee, possibly due to it's apparently weaker CPU. WD for the win, me thinks.
Disclaimer: Since Best Borrow doesn't carry them, I have no person experience with the Boxee, but the WD has blown away every other similar device I've tried, including D-Link's other offerings.