the squishees are plain ol' slurpess (obviously)
the Buzz Cola is cleverly disguised no name brand 7-11 Cola (though it tastes a bit like Jolt)
the pink donuts with sprinkles are good, but after 4 or so you start to feel a little ill
the krusty-o's are always sold out, so i couldn't tell you what they taste like
there are life size standouts of all the characters on the show, so bring your camera.
the clerks all have their nametags reading "Apu Wanna-Be" or something along the line of (your name) Nahasapeemapetalon (Apu's last name)
The plexiglass surrounding the hot dogs and taquitos has a sticker across the top that reads "BUY THREE FOR THE PRICE OF THREE!"
buy a talking Simpsons Beer Bottle Opener. Trust me.
The floors are really sticky. Weather or not this is part of the marketing campaign, I do not know.
Though for some odd reason you can't see it in xxGinaxx's pic in her post, Bart and Milhouse can be seen sitting above the Kwik-E-Mart sign as if they are looking down at who's walking into the store.
So yeah. That's all i can remember off the top of my head.