And from nokia website:

Nokia announces official Qt port to Maemo 5
Developers will be able to target the Nokia N900 and upcoming Maemo and Symbian devices.

STATUS UPDATE:
19 January 2010 -- Beta now available.
01 December 2009 -- 2nd technology preview now available.
09 October 2009 --Espoo, Finland --Nokia today announced the creation of the official Qt port to Maemo 5 and published an initial Technology Preview release. This port to Maemo 5 means that developers can now use Qt to target the upcoming N900 device and also ensures that applications can be easily ported to all Qt’s supported platforms including the next Maemo 6 release as well as Symbian and Windows Mobile.