Nah nothing like yoshi's island, you could take one look at the game and see where Nintendo "could" have taken the concept easily. It worked out for Mario and I don't really have a problem with a borrowed concept, but I wouldn't quite call it ground breaking. My friend was absolutely flabbergasted when he saw galaxy where as I was kinda like (well the different themes are cool). I don't really care who stole what, they worked well in both games and that's all that really mattered.
[edit] And as far as I'm concerned it was pretty innovative for Mario, definitely an innovative direction for the franchise, just not so much as a concept.
From 0 to KICKASS in .stupid seconds.