Nokia N900 has got a new firmware update yesterday (from v2.2009.51.1 to V3.2010.02-08).The update however is available only via N900 only not through Nokia Software Updater.
To update your N900 to the latest version,
Go to App Manager>Click on “Update”, you would be seeing an update for Maemo 5 [the total download size I reckon is 16.2 MB].
Visit My Nokia Blog post to find out more on this update.
Nokia has added support for many regions in this update (according to the users upgraded to this new version).So this might be a world-wide release.
Via:My Nokia Blog