I'm comparing the LX3 in actual use to the Panasonic TZ5, rather than a DSLR as hyped, which will make more sense in a moment...
Sensor: Bigger than the TZ5's, yet there is no significant difference in image quality I can detect. The LX3 has much lower noise in dark shadow areas, yet in normal lighted scenes, everywhere that the TZ5 smears pixels, the LX3 smears them just as badly. See RAW comments below.
Movies: For 'HD' clips, the LX3's are much better, and the sound is better. The LX3 clips are smaller, due probably to the 24 fps rate.
RAW format: This was a surprise. Whereas the Pana FZ50's RAW images (RAW converted to JPEG) were far better than those shot as JPEG's, the LX3 RAW images converted to JPEG were no better than the TZ5 camera's JPEG's, except in dark shadow areas as noted above. I was not expecting better resolution or noise, but I did expect better color rendition. The conversion was the same as the FZ50 conversions using Silkypix.
Summicron lens: I cannot discern any superior quality compared to the TZ5's Elmar lens.
24-60 mm effective zoom: This lens limits the camera to landscapes and macros. When shooting, I also carry the TZ5, and find that I'm pulling it out more frequently than I would like to capture things that the LX3 can't reach.
460k pixel LCD: This doesn't make sense, since composing doesn't benefit from the extra pixels, and playback when zooming uses the thumbnail only, so the image blurs at 4x or greater magnification.
Battery life: Better than other digicams I've used. If you carry two extras, you can shoot for eight hours or so.
Size and weight: Contrary to the specifications, the LX3 is 45 mm or so deep, yet when wrapped in a soft case, will still fit into a shirt pocket. Better use a reinforced pocket, or heavy-duty shirt.
There are a lot of things I haven't tried, but the central issue I keep coming back to is that the images under average conditions are not only not better than the TZ5's images, they just don't look anything like the hype that was generated for this new camera.