Apple has a knack of planning in advance for a lot of things. And reviewers and Apple enthusiasts have an equally persistent knack of discerning the smallest hints by Apple. With the release of OS X 10.7.3, it has been discovered that there are a number of high-DPI images in the new OS and that this may indicate that Apple may soon be releasing HiDPI Mac devices. The high-DPI images can be discerned when, for example, you see the shape of the hovering-the-link hand, which is significantly different form what it looked like in OS X 10.7.2. There are many other indications too.
Take for example another case: the hand-grab icon in the mail also looks quite different and moreover, the camera cursor that is used to select a window to take a screenshot of, also looks lot different. All these are not merely a rehash of the shape of these icons. Rather, they are a result of a new UI resource introduced in OS X Lion 10.7.3 that has the ability to scale to larger sizes. Apple has introduced this functionality in the the latest release of OS apparently in anticipation of certain HiDPI Mac devices that it may release soon.
Another thing that has been noted by Gruber is that Mac Mini owners who have now installed the 10.7.3 are automatically rebooted into a HiDPI mode after the installation. All this points to a HiDPI future for Mac. Some time back, a report by DigiTimes also claimed that Apple will launch a MacBook Pro with a whooping 2800*1800 display in the second quarter of 2012. So far, the indication have quite clearly affirmed this claim.