The Halo FAQ on Bungie.net has a couple of new entries (thanks Frans) with details on beta and demo plans, saying a playable demo will be released shortly after the PC version (hopefully not the same shortly that the PC version is following the Xbox version) and that while they are definitely planning to beta test the multiplayer component, they are not sure whether testing will be private or open. They also have a reassurance that the Mac version will have a "near simultaneous" release with the PC version.