I stumbled across this just now.
http://www.hanselman.com/blog/HowToSignIntoWindows8Or81WithoutAMicrosoftAccountMakeALocalUser.aspx

>Ok - so the trick must be to log into windows with your MS account, then log in with your regular username/password - but DO NOT DELETE the windows's account that has the MS account - which is what I did it hopes it would just ask me for the MS login info when I clicked on the tiles. I wonder if it works without connecting to an AD. Anyway it sounds like it is indeed possible to do what I want. Now in my case I will be the only user on the tablet - but I wonder if you had more than one user setup how it would know which MS windows account to link to which regular account. I guess only downside of this is that you have to create an additional windows account to get this all to fly right - that kinda sucks but oh well.