All of the following computers play Blu-Ray rips using commercial software without any problem. Here are the results with VLC 1.0.
Computer 1: HTPC with AMD Athlon 64 X2 4400+, Vista 32, 2GB, Nvidia Geforce 8400 GS
Not enough power to play Dark Knight (slideshow). Hardware assisted decoding now working. Audio seems ok. Plays TrueHD audio track fine (5.1 analog). I'm unable to determine if audio is played in full quality. Very frequent VLC crashes.
Computer 2: Dell Studio Studio 16 XPS notebook, P8600, ATI Mobility Radeon HD 3670, Vista 64, 4GB.
All Blu-Ray rips play video normally. Frequent VLC crashes. TrueHD track causes Dark Knight to slideshow with 100% CPU (64% with DTS).