Ok, here are some more in-depth steps. Locate the EXE which launches the game and right-click. Choose "Troubleshoot Compatibility". When prompted, choose "Troubleshoot program". Then check the box for what problem you are having. For example, I selected "The program opens but doesn't display correctly." On the next screen I chose the default for the large-scale fonts, where it will then scale the DPI when running the EXE.
Note: I have done this for World of Warcraft and now Portal and Half-Life 2. It seems to correct any display issues that were occurring prior to this. I don't know if there is a way to have all apps do this by default, but I'm going to keep testing out other games to see if it's something that needs to be set rather consistently.
Edit: I've confirmed that Half-Life 2 and Portal will run pretty smoothly on the Pro
This is pretty awesome news.