Not yet, but close...dpreview has handled one and posted a preview:
http://www.dpreview.com/articles/panasonicdmcl1/
Not serious for me because I prefer the 3:2 image shape of classic 35mm images and have lenses waiting to go on the digital Leica M8 - but if you are into 4/3rds, it will likely be a terrific camera. Unique selling points vis a vis Olympus are the Leica lenses and analog controls (shutter dial, aperture ring) - and image-stabilization. Likely some fast (f/1.4-f/2) compact single focal length lenses eventually compared to Olympus's stable of fast (but biggish) zooms.
Leica has officially committed to joining the 4/3rds consortium, but has released no information on what it will sell or produce itself. This will likely be announced at PhotoKina in late Sept. this year. A Leica version of the L1 is highly probable, but still mythical.