Well I've just tried kalemsoft media player. On the few times the connection to the server works, it constantly lags/drops out even with the buffer turned on. PQ is far worse than the ipad streaming from the same server in 480p.
Tried the upnp media streamer but I just can't get it to play ball no matter the transcoding setup on the server side.
I got this thing mainly for media and it seems I'm going to have to re encode films I want to watch and drop them over usb as wifi streaming seems very buggy.
I spent all last night doing the round I normally do on the ipad on the TP, crashed halfway though a skype call then crashed after a reboot while starting the call again in video mode.
I find the web browser to be usually ok, even if it's laggy but it has caused a system lockup once. Sometimes it just doesn't want to play ball until I reboot luna or in some cases a os reboot. Card based tabs is an odd way of doing things but makes sense given the platform, switching tabs is much faster than on the ipad but moving to new ones is much slower.
I love the audio performance of it. Both the built in speakers and the headphone amp are a step above the ipad with a full deep, clean bass and rich high tones on the headphone jack. Streaming web audio just works, an absolute keeper for these reasons alone.
Battery life is weird, last night it was sipping power, this morning it ate 30% in an hour.

Usage was roughly the same. Also, brightness sensor seems out of whack, when it's bright I get low auto brightness and when it's dark it blinds you. Setting manual solves the problem, odd never the less. Screen is fantastic quality if a bit low res like the ipad.
Comming from an ipad I've been spoilt for choice with apps, moving to android market was an eye opener to what alternatives are like. The TP app store is poor at best. The odd app I want is usually designed for the pre.
I didn't get the chance to have the HP case when I ordered my touchstone but I've found my 'old' ipad2 folio case fits the touchpad pretty well. So that's its home for now.
All in all, I can't wait for a public android release even if it's 2.2. I know the touchpad was used as a testbed by qualcomm for android so it should be only a matter of time before it gets out.
Those are my 24hr+ thoughts. and about 400 'I's'.
For the £105 paid I think it's absolutely amazing. If I'd have paid £480 for it I would have been extremely disappointed. At that price point you're mad to not go for an ipad2 or transformer.