For me, I don't think it is relevant anymore. If you provide great content and gets people interested, people will scroll beyond the fold.
Here's a nice demonstration.
iampaddy.com
With scroll wheel, trackpad, touch screen. It isn't hard to just go down the page for content, I believe people would think scrolling beyond the fold is actually necessary now to create the illusion of added value.
Getting the fold to work on screen sizes isn't hard (with the improvement of CSS and browser support), but it takes a massive effort to ensure all sizes are supported the way you want it and there is no guarantee in future proofing it.
Having said that, its always a case by case. It always depend on what your are trying to achieve.