HDMI, DVD-A & SACD seem to be the emerging features in DVd players
DVD-Audio is already found on Panasonic DVD recorders. SACD is bound to follow on Sony models in the not to distant future. Maybe Pioneer will add 'universal' support to their future DVD recorders?
Panasonic, Toshiba, Philips and Pioneer are all going to add HDMI onto their machines at some stage. Panasonic is likely to include it on their 7 series plasmas and, thereafter, on their DVD players/recorders.
Personally the biggest 'development' I'm waiting for is inclusion of a terrestial digital tuner. At least then we will be able to record in best quality format even if we have to wait for HDMI to be able to watch it!