Yeah AutoTune is not going to show up on an android app. There is an open source AutoTune made by a PHD student called Autotalent. I think the best shot of android getting some type of auto tune app is a developer using that.
It's a fun little app to play with for about 10 minutes, but beyond that it's kind of boring.
Apps like this is really what sets Android and the Iphone apart, if you ask me. An app like this wouldn't do well in the Android Market, because so many great apps are free. In addition to that, people would play with this program for about 20 minutes, get bored of it, and get a refund. From the developer perspective, it's not a great deal because they have made a product that people won't hang on to for long enough to make the sale final. Personally, I like it being that way, because we aren't having to spend a few bucks at a time to check out a new app only to find that it's not really that great.
On my Ipod Touch, I have downloaded probably 10-15 apps that I've had to pay for, and of those, only about 2 have actually been worth the relatively small cost. On Android, if I pay for an app, I have 24 hours to decide if it's actually worth purchasing. It sucks for some developers, but it's a great system for the consumer.