iPhone 4 apps automatically scale up on iPad?

I thought I read/saw/heard something saying that apps built for iPhone 4's Retina Display would automatically run at 640x960 when installed on a开发者_如何学Cn iPad. However, can't find any documentation on that specific feature, and my app still runs at 320x480 when installed on an iPad.

Is there a step I've missed to make this happen? Or did I just imagine this being a feature?

Apps do not auto-upscale, BUT if you have an image larger than the UIImageView you are placing it in, you will get as large a version as the iPad can draw.

I don't think it knows to pull in @2x images, just ones that are actually larger than the space you are placing them into.

This is not the case; currently, apps won't auto-upscale on an iPad. Perhaps Apple will add this in iOS 4.x for iPad, but certainly there's been no indication from them that they will.