@chernaudi: Your Audi fanboyism is clouding your judgement. In the Peugeot Sport video about the Le Mans test day, there is only one moment where a light mist of smoke is visible. However, on the Sebring test footage the R18 is smoking very badly on a number of shots; see
http://www.youtube.com/watch?v=S9e15hs_T0k#t=1m22s.
VTG is not a miracle technology that can get completely rid of turbo lag. The big turbo of the R18 has to produce 2 bar boost and feed a 3.7 liter engine, while the small turbos of the 908 only have to feed one 1.85 liter cilinder bank.
If the Peugeot engine indeed smokes very little, they may be in a position to lobby with the ACO to enforce the no smoke rule.