Can I upgrade my Android if i have low resolution?

I have a Samsung Galaxy Y Pro, which is a touch-and-type device, so the screen is small (2.6"), and I was wondering if i upgrade from my android 2.2 to android 3.0, will the display be as it should, or not? Many apps that are not designed to work with small screens will turn sideways, and i'm afraid that's going to happen if i upgrade my android.