This is no joke. It seems it's confirmed that I will need to buy a totally new PC to supprt HD-DVD or Blu-Ray. The CPU requirement is quite demanding.
http://www.cyberlink.com/english/support/bdhd_support/system_requirement.jspCPU
Intel Pentium EE 840 (3.2 GHz)
Intel Pentium EE 955 (3.4 GHz)
Intel Pentium D 9xx series 945 (3.4 GHz), 950 (3.4 GHz), 960 (3.6 GHz)
Intel Core Duo T2xxx series T2500 (2 GHz), T2600 (2.16 GHz), T2700 (2.33 GHz)
Intel Core 2 Duo E6xxx series E6300 (1.8 GHz), E6400 (2.13 GHz), E6600 (2.4 GHz), E6700 (2.66 GHz), E6800 (2.93 GHz)
AMD Athlon 64 FX series FX-60 (2.6 GHz), FX-62 (2.8 GHz)
AMD Athlon 64 X2 series 4200+ (2.2 GHz), 4400+ (2.2 GHz), 4600+ (2.4 GHz), 4800+ (2.4 GHz), 5000+ (2.6 GHz)
AMD Turion 64 X2 TL-60 (2 GHz)
System Memory (RAM)
512 MB or above, 1 GB is recommended
Disc Drive
Blu-ray Disc drive or HD DVD drive
Graphics Card
NVidia
GeForce
6600 GT
7600 GT
7800 GTX 512
7900 GX2
7900 GTX
7950 GX2
ATi X1600 series
X1800 series
X1900 series
Video RAM
256 MB graphics card memory or above
Display Devices
HDCP (High-Bandwidth Digital Content Protection) compliant display (DVI, HDMI connections) for digital output
TV (composite, componet, S-Video) or computer monitor (VGA) for analog output
Operating System
Supports only Windows XP with Service Pack 2 installed
Software
PowerDVD HD DVD or BD version. Note: An easy way to determine whether your version of PowerDVD supports Blu-ray Disc or HD DVD is to look for the Blu-ray Disc or HD DVD logo on the main screen of PowerDVD. If you don’t see either of those logos, it is likely your version of PowerDVD doesn’t support Blu-ray Disc and HD DVD title playback.
Apparently there's no recommended audio card. I suppose the codecs for DolbyTrueHD and DTS-HD have yet to be provided to manufacturers. Also it seems the immense data streams on the HD is not only memory intensive (reuqiring 1GB as its recommended level) but also CPU intensive to require dual core processing. And also wider I/O bus speeds allowed by newer motherboards.