Not sure this will help but, HTC has an upcoming tablet called the Flyer (to be possibly launched with Sprint under the EVO View name, or something like that)
They've certainly designed it with pen-input + portability in mind. Though their insistence on using their Sense skin means you'll have to deal with their custom overlay (which I found useful in a phone, but have yet to be convinced will benefit a tablet).http://www.androidcentral.com/htc-flyer ... first-lookhttp://www.carrypad.com/2011/03/04/htc- ... tion-test/
Asus also has an upcoming stylus-input 7" tablet.
Past that, I'm not sure if the android environment will suit your needs. There's certainly note-taking apps, and I'm sure both tablets will ship with some custom software to take advantage of the pen.