The new 16mm Sigma lens is now shipping in EU and USA at Wex UK, Amazon Germany, BHphoto, Amazon and Adorama.

Imaging Resource tested the new Sigma lens and concludes:

The Sigma 16mm f/1.4 DC DN Contemporary lens is a solid choice for Sony E-mount and Micro Four Thirds shooters looking for a wide, fast prime lens that doesn’t break the bank. The optics are mostly impressive, capturing sharp, detailed images in nearly all situations. With some small nitpicks aside, including a poorly-designed lens hood and some issues with aberrations and flare, the lens is very good.
Taking into consideration its price point, build quality and the pros and cons of its overall performance, I think that the Sigma 16mm f/1.4 DC DN Contemporary is a good lens and could be a great choice depending on your particular needs.

Leica 50-200mm lens at BHphoto, Adorama, Amazon, Panasonic.

Photographyblog tested the new Leica 50-200mm lens:

The Panasonic Leica DG Vario-Elmarit 50-200mm f/2.8-4.0 ASPH Power OIS Lens is an excellent lens which would make a fantastic addition to the kit bag of lots of different kinds of photographers who own Micro Four Thirds cameras. 
At just shy of £1,600, the Panasonic Leica DG Vario-Elmarit 50-200mm f/2.8-4.0 ASPH Power OIS Lens represents a fairly hefty investment – but its high quality construction and the excellent images it produces make it a lens that comes very highly recommended – especially if you’re a wildlife, sports or action enthusiast.