I've discussed this with a few people earlier, but I'd like the Tamagotchi Friends website to be a bit more sophisticated. The previous TamaTown/Music-City was poor quality, people could log on as a character without even having a Tama-Go. Whether this is going to be a promotional site or a virtual world, I don't know - but I'd like the site to have something special and be more secure, so only owners of the Tamagotchi Friends can access the perks of the site.
As for the Tamagotchi itself; I'd like it to still be able to connect with the previous TMGCs, the V6 and Tama-Go, because I have both of them. I'd also like it to keep Mametchi as a perfect adult, since he's been the mascot (with Memetchi and Kuchipatchi), on the previous versions. Some new abilities like being able to grow a plant will be great too, I've always wanted to do things like this on an American/European Tamagotchi.