This morning we have this picture, and it looks like Forgeworld is putting out a new release in the near future. This picture is the source of the rumors, and here is where it comes from.... (you will need to read german)
According to WD for release in june
it has over 40 aircraft
It is intended I beleive to update existing flyers into 6th edition.
I am still looking for details on this one, but they are rather sketchy atm.