http://www.pocketgamer.co.uk/r/Mobile/The+Simpsons+Arcade/news.asp?c=17210 "It's out there now, although hunting it down is a bit irksome. And if I know EA Mobile (and I don't), I can't imagine a big franchise like this not appearing on iPhone soon, so stay tuned for more news on that front." answer from EA on twitter to simpsons arcade on iphone: "You will see it on iPhone soon enough."
There's already a thread for this. http://forums.toucharcade.com/showthread.php?t=36693&highlight=simpsons+arcade