I see this new note on the Adobe Alchemy labs page: "Domain memory (used by Alchemy) and Stage3D hardware acceleration – when used in combination – will be part of a premium tier of capabilities for gaming in Flash Player, enabling a new generation of immersive online games."
That reminds me: I noticed that humblebundle.com is apparently involved in the purchase transactions for the recently released 'English Country Tune'. So maybe there's more afoot than just the bundles themselves:
The slightly longer and more correct answer is the source release contains the game engine source and the Doom 3 and RoE game DLL source. The Doom 3/RoE game data is still required.
It includes the source code for the expansion pack game dll (in d3xp). You'll still need the original RoE assets (when I went to install them on Windows, the installer crapped out because I wasn't on Windows 2000 or XP, but you can just copy them from a directory on the CD- they're in a d3xp directory or something like that).
I'm not sure where I picked up the info, and I haven't looked at the code to confirm it, but I believe the physics engine implementation is tied tightly to both the collision detection system and the entity update, both of which are quite specific to Doom (in particular, each entity steps physics independently, rather than a whole simulation advancing at once as is common in 'pluggable' physics engines like ODE, Havok etc).
Also, and this is subjective I suppose, I don't remember Doom 3 doing anything that 'felt' or looked better than even what the contemporaneous engines did (such as the version of Havok used in Half-Life 2).
So I guess, there probably aren't valuable additions, but I imagine there is much to tinker with.
From looking at the game code, I see odd things like rolling barrels animating their rotation as though the physics engine itself doesn't handle rolling contact.
Unexpected, but not without precedent. XNA on Xbox/Windows Phone 7/Windows, Unity3D across its range of supported platforms; it'll be interesting to see with Sony come up with.
Microsoft and Sony are direct competitors with XBox and Playstation and they have a history of doing the exact opposite of each other. Unity3D is a third party system, in the same way Unreal Engine is, and what third parties do isn't surprising one way or the other.
What is surprising is that Sony has taken a Microsoft invention and said "We'll be using that too". Not, "We've created something brilliant (and oh, yeah, it looks just like this thing from Microsoft)", or "We're using Java", or "Dalvik" (since Playstation Suite taps Android devices too).
He may be referring to Scaleform (or another Flash GUI library; I don't think he specifies), but he's also talking about his experience with scripting in Doom 3- which I'm fairly sure didn't use Flash.
RAD game tools, purveyors of lots of 'middleware' for games, have developed their own Flash playback engine called Iggy. I don't know how it rates, but its an option: http://www.radgametools.com/iggy.htm
So it's "when used in combination" (with Stage3D from my read of it). Here's the page: http://labs.adobe.com/technologies/alchemy/