Needless to say Blu-ray also supports the usual highly-compressed lossy Dolby and DTS audio formats which are unfortunately standard for most video recordings, but they are essentially irrelevant for high-resolution audio due to their low data rates and lossy nature. Audio information is deliberately thrown away in these lossy, compressed formats which completely opposes the principle of high-fidelity sound. HiFi is about accurately preserving and presenting as much audio information as possible, not deliberately discarding it.
SACD, DVD-Audio and HD-DVD are all essentially dead formats. DVD-Audio stalled not long after it was launched, and new SACD releases have slowed. Toshiba pulled the plug on HD-DVD. Blu-ray has won, for better or worse. But Blu-ray does have plenty of capacity for excellent audio (as did HD-DVD, DVD-Audio and SACD). It's up to consumers to demand high-quality, lossless audio from the producers of Blu-ray discs, and for content producers to take advantage of the high-quality audio capabilities of Blu-ray in order to offer excellent recordings that exploit them fully.
Oppo has come out with the BDP-83, a universal Blu-ray, DVD-Video, DVD-Audio, SACD, CD player that is getting good reviews as of July 2009. It's probably worth checking out. Turns out Oppo is in Mountain View, California.