Quick update for actual fans (rather than trolls) who look at this. Turn 10 has confirmed that you don't need to update on day one, you will need to in order to complete the "campaign" because they are working on bringing new free dlc that comes on day one but isn't necessary to start the game. I'll say one thing, MS isn't making it easy for itself giving all the fanboys ammo with their mixed messages.
Hey again Morgan, we know you as the Sony fanboy now : - ) Forza has never been about weather effect. The gaming engine focuses on the racing on dry weather track conditions at temperatures that are correct for the countries; and focuses on getting the simulation of the physics and handling of the car to the most realistic accuracy that surpasses every other consumer video game available. The only other game that comes close to this is the later F1 series by Codies. With this in mind; they don't focus on crash damage effects, but do focus on internal component damage effects. Combining Forza of past with a force feedback wheel; you would be able to tell when the front right suspension was damaged even by the feel of the wheel, let alone visual indication.
After thoroughly enjoying some track days, and being a great fan of the GT series in the past; I was amazed at how close to reality Forza 4 was. With the ability to play over 3 screens to have a surround vision; it was immense.
Looking forward to more with F5. Even if Forza 4 was just given a graphics boost; it would still beat everything that's on the market for realism of physics; something that I have wanted since my track days. I still have some of the older (and more fun IMO) GT games that I chuck on now and then for some arcade fun; it's a different style of game really. NFS:Shift was interesting; but lacking still. If I want night racing; I obviously wont go for my Forza game. But if I want realistic racing; I will.