You guys probably know that the 5.1 is the same old rehashed SB Live! we've seen a million times except with one more analog output.
It's really doubtful that the card will have true onboard Dolby Digital decoding. What it probably will have, just like every other 5.1 card (Santa Cruz, etc) is fake 5.1 imaging. While it sounds really good, it's not true "Dolby Digital".
I for one don't see what use 5.1 output is good for anyways? Wouldn't anyone who wanted Dolby Digital output already own a nice receiver with this feature built in? I myself feed my receiver with the SPDIF output of my Vortex2 based card.