Definitively Maemo 5 for N900.
The user-interface rocks. What are they ever going to improve about that?
Intel as as strategical partner is going to influence that for the better? Not so sure.
Bring new and plenty of icons on your MeeGo desktop: most likely.

We may be looking another Android with wider focus that has functionality wise nothing to add to the platform of mobile phones/ or pocket-able computers.

Of course I will check out Meego when its value has been proven and sung upon.

But right now, concerning the N900 I have a feeling that Meego is going to break what is just about to be nicely fixed.