Yes, there's always a but.
I picked the Panny LX5 basically because there really isn't much difference in the photo quality to justify the $300 difference in retail. The red dot is tempting, and if they do come out with a D-Lux 6 with significant lens improvement this year, I may as well upgrade to the red dot version.
As RJW pointed out, of the $300 difference, you do get Adobe Lightroom which is an amazing tool to have.
Also not mentioned is that a Leica have much better resale value than a Panny, even though they are essentially the same thing rebadged. So you may pay more, but when you sell down the track, you'll get more back, which sort of compensates for the greater initial outlay.
In any case, looking forward to middle of the year... and see if Panny announces any LX6, which would be an indication for a DLux6 a couple months later.