Tizen is a bit of a mystery actually. If all they have to show is this, then it definitely is the new meego proper. http://www.sammobile.com/2012/03/11/...hows-up-video/
MeeGo (proper) can (or at least could) be installed in the N900. IMO years of development, no advancement. Seems to be more of a hobby for a few geeks than an OS meant to be used for everyday tasks. It doesn't even look like Nokia was into it at all.