Just out of curiosity, I checked availability at Newegg for motherboards with both PCIe-X16 and AGP 4x/8x slots - out of over 450 motherboards offered, nine had this feature (4 AMD, 5 Intel CPU). I don't think it's exactly a mainstream feature (less than 2%), but if you're not sure, it doesn't cost anything (except a little time) to check.