Because if you do, then have I got the game for you.
Prepare to be shocked: I never owned an SNES. That and N64 were the two Nintendo systems that I somehow missed out on. I think because my family went Sega for a while there, and totally screwed with my Nintendo mojo. That said, it means I missed out on a lot of these beauties until my high school years when my dear and darling friend Janelle-o had an SNES which we spent hours upon hours playing. I have also had to relive the beauty of these games on my Gamecube, and, if I wasn't so cheap, I suppose I would enjoy them as downloadable content on the Wii.
I had to tell you that story to say that I didn't have a lot of experience with Yoshi's Island when it first came out, although I did play it in high school, and I remember it being a lot of fun. And it ports extremely well to the DS. It seems to me that it ported so well, that it is the exact same game. I don't know if they had to change a thing! If they did, I certainly can't remember. In fact, there are unlockable mini-games on the DS version, which might even be an awesome addition to the SNES version.
I love purchasing these golden oldies on my current handhelds. It is so awesome to relive games that I loved then, and still love now. Maybe even love more, because I can play them anytime, anywhere...(when the toddler isn't looking.) If you have a DS and a love for Nintendo, or even just a love for fun adventure side-scrollers, go pick up Yoshi's Island DS. It is a blast from the past.