Ah, I wasn't aware that there were other Mario RPGs other than Legend of the Seven Stars. (Coincidentally, Square Enix happened to be involved with that game. xD) But yeah... no matter how good a game is, I probably wouldn't last long if it has random encounters, due to my lack of patience for them. :c (Otherwise, I most definitely would've played EarthBound Zero, since I'm a huge MOTHER/EarthBound fan.) An odd exception to this is Pokémon, but that's probably because the difficulty of Pokémon games is dramatically lower than most games I've played. :P
Yeah, I'm also guessing that there will be more than one game. However, if that's really gonna be the case, then I imagine that the story would most definitely be expanded as you had hoped, because what other content could fill up multiple large-capacity games? (Besides high quality music and graphics, haha.)
Ah, I live near the Atlantic Coast of the U.S., so my timezone is EST (which translates to GMT -5:00, I think). I'm not sure what day I'll be available to play yet, but it will most likely be at night, after 9:00 p.m. EST.