Best Approach for Universal Binary?

What's the best apporach to create a universal binary with MMF that plays in Iphones, IPods Touch and IPads?

I mean, do we have to mantain a separate project for each resolution? Or can we have one project with one resolution and let the runtime scale it to the proper device's resolution?

If the latter, if I choose 640x960, will the runtime scale it down to 320x480 for old devices, and display letter boxes for iPads (and or re-scale it for iPads to 1024x768)?

If i choose 320x480, will the game look weird on retina display (X2)?

I think things are going we will have to make games for the retina and scale display in the old devices.

And an HD version for the iPad in 1024 * 768, because when Ipad scale in full screen makes a strange and not working properly.

I see. What I'd like to know in case of the retina ones, when the game is played in old ones, does the runtime scales it down for you?

François? Andos? Anyone?

BHGames passes here ...

http://www.clickteam.com/epicenter/ubbthreads.php?ubb=showflat&Number=225616#Post2256 16

I see.