YAY!!
Finally I must say.
Can't wait till autumn.

THX gebx for bringing this point

that is SOOOO important
and this is a point that SO MUCH reviewer forget to say

realistic visual damage deformation =/= realistic "car impact" physic

The only failure of GT is BUMPING when 2 cars enter in contact.
Just correct this and GT will kill every racing game (2008/09)

good news.gt5 will realy sell a lot

 Oh wow, so if the "deformation" does not affect the car's performance, then what's the point?  As a matter of fact, I don't like the fact that you have to BUY/DOWNLOAD something to make the game SEEM more realistic.  Damage and stuf like this is supposed to be included in racing games, right?

I thought this game was supposed to define what a racing game should be like and with an announcement like this, it's already going downhill.  Oh well.

Forza already does the car impact physic. However, it *cannot* be realistic due to a variety of reasons, including the manufacturer's requirements.

As all racing sim fanatics know, Forza damage does affect car handling and performance. For example, if you downshift when driving too fast you will damage your engine and risk spinning out (unlike GT4 where you seemingly automatically spin out, which is ridiculous). The amount of damage depends on how badly you overrev your engine, and simiarly other aspects of car performance (including the drivetrain) can be damaged with impacts. Further, repairing the car comes out of your credits, which means wins will generate less money for you if you aren't careful, even if you keep your car in "good enough" shape to win, or if you bump your opponent to win. 

However, this cannot be "realistic" because cars are not allowed to turn over, etc. So you can smash someone at full speed and while your car may not drive away from the accident, it will stay on its wheels.

Even if the deformation in GT5 doesn't affect how the car performs, which would be a big disappointment, it would still be a very big step in the right direction because it would affect how people would race.  If you're trying to win credits and you risk losing that many credits with a light hit, you'll be careful not to hit anything.   That might make the "ice skate" physics in GT more frustrating, though.