@ sieanr
1. There are PS3 titles that are below 720p as well, so this is also a problem the PS3 has.
XBox 360 to PS3 ports don't count, a Wii game engine and 480p game art ported to the PS3 may well result in a 480p game for the PS3 without investing a lot of additional work, so it would probably make more sense to port the game to the PS2 and let the PS3 emulate it.
Halo 3 is made by a Microsoft owned company, the most high profile game the XBox 360 will likely ever get until maybe at some point a Halo 4 gets released, a project with endless resources and more development time than anything currently on the market for the XBox 360 and PS3 today. IMO it's hard to compare expectations of a game like this with a cross platform (so far less platform specific optimised) far lower budget 3rd party game.
2. Look into how this game is being rendered to understand why it lacks AA. Beyond3d has several threads going on about Halo 3s rendering engine - so for someone so concerned about these issues maybe you should look into it there. I suggest reposting some of the things you've stated here, such as lower res because of DVD and desire to avoid RROD.
I regularly read Beyond3D, I understand Bungie's claims on why Halo 3 cannot run in 720p and without AA on the XBox 360, but I don't agree. I think the game could have been made to run just as well and look better in 720p. Also on Beyond3D people are questioning Bungie's clarifications.
Still waiting for you to talk about Lair, a game developed by a former Amiga developer, robbing the player of 120 pixels.....
120 pixels?