AirDisplay, a $10 application that lets your iPad function as a second (or third, fourth, etc.) display for your Mac/PC, was just updated to allow it to push HiDPI pixels to the new iPad. We explained it all here.

As noted by MacStories (image above), the update is live. The release notes follow:

To turn on HiDPI, you just go to the Displays Preferences and select 1024×768 (HiDPI)…HiDPI has been shipping with Mac OS X for some time. But it isn’t enabled in the System Preferences, because until now there hasn’t been a mass-produced computer display with high enough resolution to do it justice. That’s where Air Display and the new iPad come in.

What’s New in Version 1.6

HiDPI • If you have Mac OS X Lion and a Retina iOS device, now you can turn on “HiDPI mode.” HiDPI is a built-in Mac OS X feature that makes UI elements render at double resolution. It’s absolutely stunning on a Retina display. By default, Mac OS X disables HiDPI because until now, there has been no Mac display with high enough resolution. Air Display on a new iPad, with its 2048×1536 264-dpi Retina display, finally brings HiDPI to life.

RETINA DISPLAY • Devices with Retina displays now can optionally render at high resolution. You can still choose to view at non-Retina resolutions. • Air Display now uses the full screen resolution when scaling (while doing video out or mirroring a larger device).

BUG FIXES • No longer disabling drivers on MacBook Pro models with NVIDIA 9400M/9600M video adapter. Please see avatron.com/lion for more information. • Fixed bugs related to modifier keys on the virtual and Bluetooth keyboards, when connected to a Mac. Requires Mac Air Display Connect update. • Fixed the “Enable Keyboard” option (in the Air Display section in the Settings app). • Improved frame rate and quality. • Fixed video output bugs.

  • Air Display update makes iPad a Retina monitor for Mac, enables HiDPI mode (9to5mac.com)
  • What the new iPad and Mountain Lion tell us about Apple’s upcoming Retina Macs (9to5mac.com)