Just took the time read through all of this thread, and I must say unless you actually own a PS3 you really can't truly understand its limitations as a media device.
The only advantage the PS3 has over the Apple TV is its wider array of codec support. However, even that is flawed. Sony purposely limited both WMV and DivX playback to 2GB. I would assume this artificial limit was imposed to prevent playback of pirated HD files.
The media interface on the PS3 is archaic. You have to navigate a directory-like structure of files in each category (Music, Photos and Video). Thumbnails for music and video are not available unless you copy your media files to your PS3's internal hard drive.
The PS3 supports FAT32 external drives only. Therefore, all files must be 4GB or less and have shortened file names.
Media streaming is limited, and wasn't even reliable until the latest firmware update. There's no automatic media syncing support.
The PS3 lacks an RSS aggregator (no podcast support). There's no movie rentals or TV shows available from the PlayStation Store.
I could seriously go on.
You would think Sony who owns Sony Pictures (Jerry Maguire, Jumanji, etc) and Sony Pictures Television (King of Queens, Seinfeld, The Shield, etc) could come up with something.
Not to mention, Sony Computer Entertainment owns a tons of software properties even iTunes-like applications (SonicStage, etc).
The PS3 is the best Blu-ray player you can buy, and has some cool game titles that are coming soon (Little Big Planet, Metal Gear, wahoo) but the notion that the PS3 even remarkably competes as a media center-like device is a complete joke.
The problem is not the PS3's hardware, it's a powerful device. It's the software. I mean do these divisions talk to each other? What's with the lack of integration?