It's not currently in a stable or complete state, due to time constraints for the developer. See http://talk.maemo.org/showpost.php?p...7&postcount=25
I was looking into picking it up at one point, but I don't have time either at the moment. There is an experimental Canola plugin for RTM, developed for Google Summer of Code this year, however, last I checked, there had be no commits since shortly after GSoC ended, nor word from the developer.
I am in need of a Maemo RTM app, as well; I'd put a bounty on it, but I'm a student, so I'm poor as well as busy Maybe someone should?

As a note, however, I believe there is a todo app (Zutun?) that allows you to send todos to RTM, but not to view them.