I have one of those (used as an htpc) but I find the picture is laggy (although I'm using ubuntu so win 7 may help) and its a bit of a jack of all trades....
Next on my list would be an eGreat a1080 (or whatever the latest thing they bring out is) which seems to be a pure HTPC (no streaming from iplayer by the looks of it) - but pretty good for everything else.
Saying all that, it seems that blu ray players are slowly becoming htpc-ish. This sony one is cheap, plays blu rays, streams youtube, iplayer etc and has (limited) network capabilities. I would give it another 6 or so months before we start seeing proper network streaming capable blu ray players becoming mainstream
Edit, also have a look at xtreamer.net - it says its compatible with internet TV but I would check first. There are problably UK resellers on ebay.