Here are my ideas!
I think there should be 'tama time' where events come sooner, your tamagotchi lives longer, and years don't pass every twenty four hours. One tama year should be about every few weeks... this way you won't get so bored of the eveloving/dying and leaving you their offspring cycle so quickly. However, the day and night thing will be like real time.
There will be a house for the tamagotchi. You browse around the house to feed, clean and play. For example, you poop in the bathroom; sleep in the bedroom. You can buy furniture with the money you make from games. You can browse the rooms with the menu bars. The only thing that isn't a room is status, address book and connect. Other tamas may randomly come to your house. You can hire services like a milkman or the newspaper which reminds you about holidays or tells you tips about taking care of your tamagotchi. Burgulars may randomly jump into your homes. You can buy an alarm system to prevent this.
The rooms will include a kitchen for feeding and stocking up on food, a bedroom where you sleep, a bathroom where you bathe and go to the bathroom, a living room to sit in to do nothing or play with your toys and look at your certicficates and awards you win from school or work, a front lawn where you can see the weather. Some days it will be rainy, snowing, or sunny, depending on the time of year it is in 'tama time'. At night you can see the moon, and every few days it will be a full moon. You can raise a family with tamagotchis once you mate and have little kids jumping around the house. When your current tamagotchi dies (As well as the mate) you will take care of the kid. If your mate is a tamagotchi you connected to, there will be two kids.
You'll go to school and get a job when you're older. You make virtual friends at school, some grow up with you and you can mate with them if you can't find anyone else to connect to in real life.
You can also go out with your friends or dates with the tamas you love.
You must send your tamagotchi to school/work if his/her's discipline is low. If your tamagotchi's discipline level is high, he or she will automatically go to school or work and pack his/her own lunch.
There should also be a little neighborhood in the tamagotchi. It will include a park for your tamagotchi to play games and meet other tamas, a doctor's office and pharmacy to buy medecine when your tamagotchi is sick, a train station to go to work/school, a supermarket to stock up for food (Which also means you will run out when you overfeed or forget to buy.) There will also be a gift shop to buy gifts for your friends you connect with, like flowers and cake. Of course there is also the toy shop. You can also buy bigger houses with more room for furniture. Other places should be online. You might have a random encounter with other virtual dummy tamas or tamas you have connected to in the past. You either exchange gifts or just walk by depending on your relationship. The menu bar will change when you are in the neighborhood. You can unlock more buildings in the neighborhood by buying them online with your gotchi points.
After your tamagotchi comes home from work, it will bring a certain amount of gotchipoints, depending on how good it's job its.
If you have no money, you can rent your house to a roommate, one of the virtual dummies. Or better yet, someone you can connect to in real life! When both your tamas are in the same room, you can see eachother. The better your furniture and your relationship with the tama is, the more likely a tama will ask to move in with you.
They should also have more health bars for different things, like energy so you don't work them too hard. Also cleaness so you can bathe your tamagotchi and brush it's teeth before bed and breakfast. And a personality bar would be nice, too?
On festivals you go out to the park to celebrate. Your happiness and hunger points will go up, and you will get an item.
For example, on chinese new year you will get a red enevelope with gotchi points in it. At christmas, you will eat a turkey, (Hunger points) and get a gift from santa if your discipline went up at least one point from last chistmas (tama time of course.) You get poo if you were mean to other tamas or didn't do anything at all. And on valentines day, your tama friends (and lovers) give you chocolate. At easter, you can go on a easter egg hunt around the neighborhood and win a toy.
And everytime there is an update, you can download it off the internet.. for a price of course. How else would the company make money? ;]
I also agree with the backlight, vibrating and item skill ideas ^^
I wonder if all that can fit a tamagotchi..? It is awfully small..
I can still dream T_T
Btw, I'm really sorry this post is so long