Apparently, all those cars that have been listed will be available for regular purchase through the dealership. Pre-ordering will make you get them immediately upon starting, which is fine by me as long as they don't restrict certain cars to those who pre-order.
Paint chips are back? This, honestly, surprises me because I couldn't make sense of the paint system in GT5. Buying a 1000000 credit car, to get a paint chip for customizing another car is crazy, even more so when you consider each chip is only of one use. What were they thinking? Also, like user Spagetti69 stated, I think this pretty much means no livery editor.
Anyway, I'm liking the new confirmed cars. Hope they reveal more modern GTs and LMPs as well.