I have been playing around with BB10 and Playbook OS2 software.
I can confirm that Modern Combat 2 HD from BB App World works perfectly on the Dev Alpha. Graphics as smooth as you can get.
Also, i don't know if this has been pointed out, but the Dev Alpha is running an ARMv7 Processor rev 2(v7l) CPU according to a file found in the file system.
I have also tested Cut the Rope and it scales amazingly well and the display does make the game look great. Oddly enough these games are all done in Native. If we were talking WebWorks here, might be easier to comprehend because of the nature of webworks but to see native apps working out of the gate is very impressive.