<< is there any plan for a greasepencil/sketch tool in MOI ?

I suppose not nearly but what not use something like that?
Make a screenshot and use Fotosketcher (free) http://www.fotosketcher.com/ (French creator ;)

or save your object in SKP format inside Moi for the Free Sketchup ? ;) (hundred of styles!
http://www.sketchup.com

Or in AI format inside Moi for the crazzy XARA Xtreme 5 (it's free to the 29 April!!!
http://www.xara.com/us/specialoffers/designer/


Ps Have you remark that you can use a pen graphic in Moi 3D for draw your curves ? ;)