dangit! I just bought petit computer last weekend. From the screenshots though this looks like the same interface as Petit Computer. Is this a new application separate to Petit or will this be an update for Petit I wonder...

Separate, unfortunately for your wallet... This one's a proper 3DS application, whereas Petit Computer is a DSi application that was carried over to the 3DS eShop.

That being said, I don't think the new version will run programs made in Petit Computer as is without a fair bit of tweaking, so you do have the benefit of being able to try out the Petit Computer programs already made. It's not a complete waste!

I guess I have something to play around with the smilebasic syntax. I can't imagine that the language used will change dramatically to the new version..