I know this is an old thread but I thought I might still be of some help.
With an HTPC you can play HD content on your HTPC. You just need the right hardware/codec’s and stuff like that. There's already a Blu-Ray PC drive out. A HD-DVD drive will be available in the near future. You will need a HDCP compatible video card in order to playback protected HD content & a monitor/tv that supports HDCP.
Here is a list of HDCP video cards:
http://www.hardforum.com/showthread.php?t=1071342Here is a cheap (and good) HDCP PC monitor that is under $300
http://www.dell.com/content/products/produ...s=04&l=en&s=bsdHere is a good HDCP 1080P TV
http://www.crutchfield.com/S-EK317fPsC2T/c...estinghouse+LVMYou can play all your MP3’s
You can play all of your Emulators/ROMS. I’m 98% sure you can hook upto 4 wired or wireless controllers. (although going wireless would be harder I think)
You can stream media from another PC to your HTPC, You can stream internet radio, you can use a HTPC has a DVR, you can install dual TV turners (so you can watch 1 show and record another at the same time), you can install HD TV Tuners, which lets you record OTA (over the air) HD content. DVD playback, View Pictures, go on the internet, play computer games, and pretty much anything else you can do on a PC.
Also, you don't need Windows Media Center. Here is a list with quite a few of the apps you can use instead of Windows Media Center.
http://eirikso.com/2005/10/25/the-media-ce...-software-list/Here's a link to a few apps that might help you with your build. The HTPC apps are half-way down the list.
http://www.avsforum.com/avs-vb/showthread.php?t=399319You might also want to read this.
http://www.avsforum.com/avs-vb/showthread.php?t=523614http://www.htpcnews.com/index.phpHTPC Store
http://www.pcalchemy.com/index.php/cName/h...f9fac16aabcb450I hope this helps.