Great idea, I suspect it won't attract as many people as the regular videos, owing to the lack of a specific subject. So rather than dilute the EEVBlog brand, maybe call them EEVRaw or something? Just a thought anyway.
Watching the screen while you actually do stuff can be tricky to say the least. Now you have a Mumble server, how about opening a public channel when you do raw streams, so people can talk to you?