Super AMOLED HD
Super AMOLED HD is a new Super AMOLED type display from Samsung featuring HD (1280 x 720 or more) resolution. Samsung actually calls this display "HD Super AMOLED". The first device to use an HD Super AMOLED is the Galaxy Note: an Android v2.3 phone with a 5.3" 1280x800 display. The phone (and the display) was announced in September 2011. The second HD Super AMOLED device is Samsung's Galaxy Nexus phone - with a 4.65" display featuring 1280x720 resolution.
Using new manufacturing technology (and better OLED materials), Samsung managed to get the pixels even smaller now, and so the HD resolution was possible. They are still using a Shadow-Mask and haven't moved to LITI production yet. They are also using PenTile technology (which uses 2 subpixels for each pixel) to get even an even higher resolution.
HD Super AMOLED vs Super AMOLED Plus
It seems that Samsung now uses two brands for its touch OLED displays. Super AMOLED displays use Pentile, while Super AMOLED Plus do not. Super AMOLED Plus was announced in CES 2011, and are actually Samsung's best OLED displays. Samsung's popular Galaxy S2 for example has a 4.3" WVGA Super AMOLED Plus. The Galaxy Tab 7.7 tablet has a 7.7" 1280x800 Super AMOLED Plus display.
Samsung's Super AMOLED Plus displays are an upgrade to the company's Super AMOLED. The new displays offer 50% more sub-pixels, and in fact use regular RGB matrix (as opposed to the Pentile Matrix used in the first generation displays). The displays are also thinner, brighter and more efficient (by 18%) than the old Super AMOLED displays (but are probably on par with the HD Super AMOLED in that regard). Using more sub-pixels means a clearer display - even though the resolution per-inch is actually lower.
Samsung's Super-AMOLED displays features an integrated touch function over a regular AMOLED. Samsung is placing a touch-sensor (on-cell) over the display and evaporates it. The thickness of the touch sensor is just 0.001mm (!) - which allows the screen to provide better images and to have great visibility even in direct sunlight (Samsung says that this technology performs 20% better than regular touch AMOLED outdoors).
Super AMOLED HD on video
Here's a nice hands on video with the Galaxy Note, showing it's 5.3" 1280x800 HD Super AMOLED display:
Super AMOLED explained and some cool videos
Here's a nice video interview with a Samsung employee that explains how Super-AMOLEDs work and why they are the best displays around:
Here you can see how the Super-AMOLED behaves in direct sun: