They would want one big toaster where people bring bread to be submitted for overnight toasting. IBM would claim a worldwide market for five, maybe six toasters.
You could toast one-sided or double-sided. Successive slices would get lighter and lighter. The toaster would jam your bread for you.
The staff would sell you a toaster, but not know anything about it. Or you could buy all the parts to build your own toaster.
They'd claim their toaster was compatible with all brands and styles of bread, but when you got it home you'd discover the Bagel Engine was still in development, the Croissant Extension was three years away, and that indeed the whole appliance was just blowing smoke.
The toast would burn often, but you could get a really good cuppa Java.
They made good toasters in the '80s, didn't they?
They would market the Reverse Polish Toaster, which takes in toast and gives you regular bread.
You could make toast 24 hours a day, and if a piece got burned the toaster would automatically toast you a new one.
You would be able to toast 64,000 pieces of bread at the same time.
They would cost $16 million but would be faster than any other single-slice toaster in the world.
It would make the bread look like it was toasted. It could also transform rye to wheat and add whatever kind of spread you could imagine, and it would slyly imply credit for making the loaf of bread in the first place.
The ToastMan, which would be barely larger than the single piece of bread it is meant to toast, can be conveniently attached to your belt.
They'd be really cheap, as long as you bought a six-pack of 'em.
And, of course:
Every time you bought a loaf of bread, you would have to buy a toaster. You wouldn't have to take the toaster, but you'd still have to pay for it anyway. Toaster '95 would weigh 15000 pounds (hence requiring a reinforced steel countertop), draw enough electricity to power a small city, take up 95% of the space in your kitchen, would claim to be the first toaster that lets you control how light or dark you want your toast to be, and would secretly interrogate your other appliances to find out who made them. Everyone would hate Microsoft toasters, but nonetheless would buy them since most of the good bread only works with their toasters.