It would basically be a miniature PC that resembles an Android phone, but which isn't a phone, but which you can just install Skype on if you really need to make a phone call, since it could still get cellular data service.
And, being like a miniature PC, it would be as open to operating systems as a real PC; it would be just as easy to install and reinstall Android firmwares (or any compatible OS) to it as it would reinstalling your operating system on your laptop.
I imagine Dell would be a good manufacturer for such a device; they would market it just like they market netbooks, as being just a mini PC that happens to run Android (preferably the stock vanilla Android as Google intended it, but being open you could flash any version of Android you want).
If such a device existed I would buy it as soon as it came out. I'm quite sick of the way phone carriers abuse the Android OS and wish there could just be a seriously open device.