Yup, quite a tension point, system requirements are! But they've been promulgated nontheless, as YouGamers interviewed Gabe Newell on the aforementioned matter. The requirements are:

Minimum

1.7 GHz Pentium 4
512 MB system RAM
DirectX 8 compatible video card

Recommended

Processor: Intel Pentium 4 3000 MHz
Display Card: DirectX 9 compatible graphics card
Memory: 1024MB
Free Disk Space: 5GB
Operating System: Microsoft Windows 2000/XP/Vista

Surprisingly low, considering today's games are wanting SM3.0 support as a minimum and 1GB of RAM. Plus, a much faster CPU, not to mention dual+ core - but the Orange box' quality will only create itself on a much better system, of course, for optimum experience. Still, that the requirements have been vociferated denotes that the game's gold date is drawing close. About a month to go, now...

By the by: The "Meet the Soldier" Team Fortress 2 video has been released. You can find it on Steam (with a 30.9MB download) in 720p WMV9 HD, or at Shacknews, if you would. There's also a new GC2007 Half-Life 2 Episode Two video, here at GameTrailers.