I may join this roleplay, I'm just still trying to decide on who I would be good at...I usually prefer original characters to canon, but I may give it a try anyways. I may have just missed reading this, is it canon characters only or are originals allowed as of yet? As for a plot, well...what's the time line for this roleplay? You could have it go a few ways:
Great Valley Adventure: A new plot, continued from where the last movie in the series left off perhaps. Maybe have them meet a new friend or so or even meet up with friends met in previous movies. This may be fun, especially since it seems we already have people who would roleplay some of the other characters.
Journey Adventure: This idea came to me the other day, I suppose since the original still remains my favorite of the movies, a roleplay like this could take place during the group's original quest. Almost like an 'interequal', we could rp out scenes that perhaps were never shown in the movie. They're still searching for the great valley in this, their friendhips only just starting to grow and Petrie wouldn't yet be able to fly, etc. Create new obstacles for the friends to overcome, add stronger emotions to their friendships, etc.
I'll try and think of some ideas here...if it is pure canon only then perhaps I'll go wih Spike...he shouldn't be too hard to keep IC.
I'm not sure though, Petrie or Ducky may also be fun...is there a Littlefoot yet? I'll see what my options are and choose from there.