well, on one hand, you say they already have handwriting recognition implemented - so it probably didn't have to be too complicated/expensive to port it.. this is in case the maemo 5 will be used on more than just of their phones (n900), or.........

according to maemo summit, maemo6 should move towards capacitive displays, which means no stylus and thus no handwriting recognition possibility..

bottom line is that, i think, they will add it to maemo eventually, if maemo6 will support resistive screens afterall, and more than 1 device with maemo will be in production (which they most probably will), then maybe, maybe...... you can see there are lots of 'if's