The new MacBook Pro is something of a classic at this point when you consider the design has not changed that much in years. The one new thing that is very different from before is the dual video processors within the Pro. The new MacBook allows you to switch between processors to allow for better graphics power or better battery performance. The one bad thing about this process is you have to logout of the MacBook once you switch and then back in.
This could be due to a need to turn off the chip and turn on the other without interfering with the back end of the OS. The most likely issue is a lack of proper support in the current version of OS X to handle 2 video GPU’s. Snow Leopard could incorporate the use of both in SLI mode or just allow fast switching of the new video chips. Whatever the issue is, Apple will eventually fix it as they prefer a seamless experience.