I was just thinking about how I'm looking forward to some of the upcoming features when I realised that for someone who is just joining, it might all be a bit much. Right now I think it should still be quite doable, but once there are things like radical breakdowns per character and "force buttons" it might slowly get a bit much together with numbers about "readiness of a character", green-arrow click in the window for the next character, setting individual retention rate, adding special characters....
I don't know how easily that would be doable, but it might be good to just have the basic functions, i.e. writing a character and tone, for people who are absolute newcomers and just want to find out what skritter is about (I know that when I am just browsing and find something new, I don't want to spend 1 hour registering "for free" and then spend another hour on a tour....I want to enter the page and start doing:). After a short while they could then be encouraged to take the "learn more" or "adjust skritter to your needs" which activates all the other cool features.
Maybe it's a bit early to be thinking about this, but it might be something to keep in mind.
David