Seth, I'm holding off on the Blu-Ray/HD-DVD front for a while myself, but not sure I agree with your comment about the high def audio formats, at least not in the case of SACD. DVD-Audio titles are limited to about 300 titles right now, although more are coming out, like the upcoming Doors boxed set. SACD however has about 3600 titles available, again with more titles coming out all the time. I get e-mails from Acoustic Sounds, Music Direct and the Elusive Disc every week with new titles being announced.
SACD certainly doesn't have the mainstream penetration (can we say that and not get filtered?), that one of these video formats is likely to achieve, but it does still seem vital in the niche audiophile market. Hell, everyone said vinyl was dead 20 years ago, but vinyl sales continue to grow every year!