I've heard it said that new technology is accepted by half of the user population after one year. Nielsen has the charts to pretty much back that up. Frames I agree. For me it has nothing to do with page layout and design. It's all speed.
Frames are clumsy and hard to bookmark.
Yes, I know IE 5 will bookmark correctly, sometimes, but IE 5 is not an overly popular browser. All I'm saying is to think hard before going with a frame layout. Now, if I may, I'd like to offer my own Web-design concerns. Uniformity in backgrounds is the easiest way to do this. Wildly differing backgrounds are strange and often slow the site because the images need to load.