The image below was shown at French forum "forum-peugeot". It does not present the next Peugeot 408 in its final version because the car will have a new front design. The new design director at PSA, Jean Pierre Ploué, did not like the car so changes will be made. That means a 4 to 6 month delay. This is not very common and it will cost some money but not that much because it will be only a front job. And anyway, in this current market environment it's not too bad to delay a bit a big investment such as the new mid-size sedan.
The rear and profile should keep unchanged: it does have a bit of 4-door coupe design, which it's not surprising.