It's slightly annoying that you have to use marmalade to access the lower level features of the Roku. Mainly because I already created my game using Gamemaker Studio which is a paid product for cross platform game development. And now I am required to get another paid product if I want a game on Roku.
That being said it looks like they have an offer for developers right now to possibly get marmalade plus for free for 6 months. And I must say some of the features of marmalade are very compelling. I originally used Gamemaker because it was easy, but it is also somewhat restrictive in what you can do.
I hope sometime Roku either opens up the NDK, gets the Roku compiler in the free version of marmalade, or improves brightscripts capabilities.
It could make Roku your one stop platform for everything you need on your TV except of course for high end gaming.