At a recent HTC event, a couple of dudes from Android Guys managed to corner an HTC official and beat a few answers out of him (or her). The big question that got settled was that of the frustrating 30FPS refresh rate cap in place on the EVO. According to HTC, the cap has its origin in the HDMI port, out of which the phone can only push a maximum of 30FPS. So their solution was… to reduce the display rate to 30FPS throughout the entire phone, even if there isn’t an HDMI cable in sight.
It’s really a bit weird to have that cap, which is very noticeable when dragging and zooming, apply to the whole OS whether there’s HDMI connected or not. Changing refresh rates is a trivial action; as AndroidGuys suggests, it would be reasonable to expect an update that makes the frame rate adjustable depending on whether a cable is connected or not. I concur.