In a review of it, I read:
The LX5 is the fourth in the LX series, following on from the LX3, which was released in 2008. That may seem odd, but Panasonic, like other Japanese manufacturers, does not use the number 4 in its designations. This is because the number is considered unlucky in Japan, due to it being pronounced the same way as the word for ‘death’.
Woa! And nobody told Nikon! The new flagship D4 must be dead in the water. Ooooh.