Christopher Breen did some digging and came up with the solution -- you need to open RealOne Player's preferences, and disable the "Real Time Streaming Protocol" section in the Media Types preference. As Christopher points out, you might actually have to enable it once, click OK, then re-open and disable it and click OK to make the changes "stick."
Once you've done this, though, the QuickTime streams will open properly in QuickTime Player.

