First, the media streaming requires DLNA support -- not sure if your computer supports this protocol? If you're using Windows XP or Vista and have Windows Media Center 11, you've got the functionality built-in. There's some issues with streaming .mp4 files (WMC11 doesn't allow you to add these files to your Library), but music streaming worked perfectly. The Mac OS X side of things wasn't as smooth.
While there are third-party programs like Connect360 that filled in the gaping hole left by Microsoft's nonexistant Mac OS support, they admittedly didn't arrive on the scene until later and, even then, didn't offer a fully functional experience until a couple versions in. The PlayStation 3 similarly lacks a Mac OS X media server client capable of streaming your media easily. We hope Connect360 is updated to support both consoles but there are other options.
Elgato's EyeConnect turns your Mac into a DLNA-compliant media server. Upon installation of the demo, our Mac immediately showed up on the PlayStation 3. While photos displayed fine, the PS3 had trouble connecting to our music library and the EyeConnect client balked at displaying our .mp4 video files. Other solutions, like TwonkyMedia, were even less successful. Through no shortcoming in Sony's implementation, you're probably going to want to wait for third-party applications for both Windows and Mac OS to provide a flexible and fully featured PS3 streaming solution. Luckily, the upsampling feature worked much better.
PlayStation 1 (both disc and downloadable) and PlayStation 2 games displayed in 1080i on our system flawlessly, though it's worth noting these games are upsampled, not rendered natively at this resolution, so expect some blurriness (for a great side-by-side, check out PS3 Fanboy's rollover images). We also tried copying save files back onto a Memory Card, an admittedly niche feature that nevertheless worked as advertised. We'll have to wait until next week, when the PSP 3.5 firmware update drops, to check out the enhanced Remote Play functionality. Overall, a remarkably robust update that will be even more appreciated when proper streaming solutions arrive on the market.