Back in December I reported that the Leica 24mm f/2.8 Elmarit M Aspherical lens was discontinued. The lens is currently listed as “no longer available”.
Another lens, the Leica 21mm f/2.8 Elmarit M Aspherical lens is now also listed as discontinued at B&H:
If you are looking to get one of those lenses, Amazon still has the 21mm in stock and Adorama has the 24mm in stock.