With a Retina iPad 3 expected just next week, one developer has created a small utility that allows the iPad simulator to run in 2X mode. The utility is available from Ryan Petrich.
In order to run it on the latest version of Xcode, you will need to symlink /Applications/Xcode.app/Contents/Developer to /Developer and /Developer4.
Meanwhile, stroughtonsmith shows how his app SameGame looks in the Retina iPad emulator running on his 27" iMac:
Click on image to see full size.
Apple is widely expected to release a Retina-enabled iPad 3 next week at their media event. If rumors are to believed, the iPad 3 should be available within a week or so of the announcement. That would leave developers little time to Retina-ize their current iPad apps if they wait until the day of the announcement.
Top Rated Comments
could a worse example be chosen?

I think that might still actually be better.But is this hack actually correct. It seems like it isn't. From the description this emulator is making the pixels double the size akin to the blowing up of an iPhone app on an iPad. But that isn't what the retina screen does. It's more like cutting the pixels in half to shove more into the same space.
To view the rumoured four times the number of pixels, you need to double the width and height - which is exactly what is being done here. Density is hardware based (ie. the physical number of pixels per inch).I recognize the bluetooth and wireless, but what are all those other icons? What kind of really cool software does this person have?
Drooolllll.....