To get the full advantage, click on the YouTube 1080 link and wait for it to load, as its a huge (271MB) file and it will take time. There may be some "stuttering" coming off the server but it should give a decent impression of what this camera is capable of.
As with the 550D, excellent quality. The GH1 does have the well-known problems of slightly less dynamic range and a low bit rate. You can see the occasional burn out and compression artefacts. However still incredibly impressive.
The Lumix 20mm f1.7 pancake is really an amazing lens. Very sharp and clear.
Tried the video files straight into a HD televison via an HDMI cable and they look absolutely amazing. AVCHD files do look good on such screens.