I wasn't a terribly big fan of Phantom Hourglass either.
I don't mind the train. I like that Nintendo is expanding the universe because they were running out of ways to make the current formula fresh and exciting. They kind of killed the 2 worlds mechanic. Now, I'm not saying that a train is the "end all, be all" but it's something and I, at the very least, appreciate that Nintendo is trying something new.
Spirit Tracks is a totally lame title. I mean, I get it, but that doesn't make it any less lame. Link's conductor outfit is equally lame. Still, my biggest concern is that the gameplay looks pretty identical to PH which means they're following the same trend as before: minor updates to existing gameplay. I honestly didn't think PH's gameplay was good enough to carry over to a new game.