PDF can give you all the benefits of including images and styled text, corporate logos and fonts, in a handy format. You won't have to make the corporate font into an image, instead you can style as you would a printed document. You can have links between your PDF files. Knowledge is power. Maybe people feel uncomfortable about drawing attention to the reliance on Other People's Technology for an optimal viewing experience.
People appreciate even small gestures.
Instead of doing a rollover that just changes the slice the mouse is over, get it to change a different slice. Then you can set the slice to change back when you go over a different slice. And you can set the image to change whether the mouse is over, down, or clicked on, and each of these images can be different, to make a highly interactive page. And test again. Being aware of the different and various limitations of browsers will make all the difference.