Just a quick heads-up: Apple has released a new ( new ) iMac which comes with a built-in VESA Mount adapter. The iMac with Built-in VESA Mount Adapter is ready to pair with your favorite VESA-compatible wall mount, desk mount, or articulating arm(sold separately). This iMac doesn’t include a stand, so a mount is required. If you don’t already have a mount, you can purchase one when you configure your iMac.
For more info check out Apple’s webstore…