Graphics card projector compatibility

I have a 2.2GHz 4G MacBook (the latest MacBook minus one).

I am soon going to have to start giving presentations to classes etc. on a projector screen. However, the Apple website says the MacBook graphics card will only support up to a 23-inch display.

What will be the effect on the picture on a display at least twice as large as this? Will the MacBook just break down, or will it simply "fuzzify" all the stuff on the screen?

It's not so much the screen that you have to worry about as it is the resolution. If the projector has a native resolution higher than 1920x1200, then you might have some issues, otherwise it will work just fine.