The Playstation 3 decodes Dolby True HD internally, then converts it to high resolution multichannel PCM output over HDMI.
What does this mean?, it means that you don't have to buy a receiver that decodes True HD. At this point there is no such receiver, but many HDMI capable receivers can decode hi-res PCM. I do not know if the PS3 is capable of decoding DTS-HD as far as the hardware. I am pretty sure that it does not decode DTS-HD out of the box, as a firmware upgrade may be possible.
And lastly, I forgot to mention this as I was tired and forgot what this thread was started for. The Playstion 3 does NOT upconvert DVD to 1080p, only 480p. It only serves as a standard progressive scan player for DVD. However it does 1080p for Blu-Ray and select games.
The PS3 comes with the component video cables, but not the HDMI cable, though it was rumured the $600 version of the PS3, the one with the 60gig HDD, would come with the HDMI cable, I do not believe it will come with the system anyway.