from meego forum:

"Let me try to clarify the MeeGo-on-N900 situation a little for you in simple terms, at least as I understand it.

MeeGo will NOT be available for the N900 as a finished, end-user-ready OTA update soon. There MIGHT be a user-ready version of MeeGo for the N900 available at some point, that is as yet undecided. However, if so it will no doubt have to be downloaded and manually installed, IOW 'flash' your device, wiping out all installed software, etc. This is what darthjysky was referring to when he said "Think it as if one would install windows not from CD/DVD but having the complete C:\ content in a single file and writing it to hard disk." The differences between Maemo and MeeGo OS will be too large to allow a simple OTA upgrade from Maemo 5 to MeeGo.

What we have now as far as MeeGo for the N900 is a non-GUI (terminal CLI interface only) developer-only very basic OS. As I understand it, what we should see in May is a 2nd MeeGo release that will still be a developer-only version, but with basic GUI elements and some other stuff added. But it will still be a long ways away from being ready for installation and daily use by ordinary users.

However, what the N900 WILL get any day now as an easy OTA update that is a significant upgrade to Maemo 5 adding some nice features, including adding critical Qt 4.6 compatibility. Qt compatibility ensures most (if not all) software written in the future for MeeGo will run on N900s still using Maemo 5. And we likely will get at least one more significant upgrade to Maemo 5 sometime after that. At that point the N900 will have gotten 5 updates total, and possibly could get even more. That is unknown at this point.

Anyway, bottom line is all this ensures the N900 will have a long, useful life with or without upgrading to MeeGo. So if you want a N900 and it suits your needs, go for it and don't worry about whether or not you get MeeGo on it, it's still an excellent unit."