Here is a comment on this new pyramid by Franck Monnier, who recently authored an excellent book on the pyramids :

"A NEWLY DISCOVERED PYRAMID AT DAHSHUR ?

Being away during a few days, without internet connection, I've learnt today the sensational announcement of the discovery of a pyramid at Dahshur, in which were uncovered some fragments bearing the name of Ameny Qemau.
As systematically now, the official announcement shows some pictures, does not mention any name of Egyptologists, and does not say very much; Just enough to attract interest of the world's newspapers.
Then, is this a second pyramid for Ameny Qemau?
I remember that another one was attributed to this pharaoh. It had been spotted by Muses in 1957, on the site of Dahshur also, and later studied by Nabil Swelim.
When we compare the recent pictures showing a well-defined monument (it is surprising that nobody has spotted it before this broadcast) with the satellite view of Dahshur, it seems that the two pyramids are only one. One notices this levelled structure, with an east-west passage interrupted by a lintel. In addition, one of the photographs shows an inclined plane located just behind the location of this lintel. This slope had to accommodate a heavy sliding block to seal the passage. The drawings of the "first" pyramid of Ameny Qemau made by Nabil de Swelim show an identical arrangement (descending passage, lintel, and inclined plane).
Then, this new pyramid would be the one situated at the south of the bent pyramid (and not at the north). Very strange...
I fear that we are dealing here with recycled "news"."

Franck gives with his comment this image: [scontent-cdg2-1.xx.fbcdn.net] (satellite view of Dahshur)
and Steve Harvey provided a drawing of the "first" pyramid of Ameny Qemau made by Nabil de Swelim that shows an identical arrangement (descending passage, lintel, and inclined plane): [scontent-cdg2-1.xx.fbcdn.net]
(I hope the links to the images will be ok!)