The Bioversity's Musapedia is a good place to start for reliable information on this, as is the FHIA (Fundacion Hondureno de Investigacion Agricola), one of the world's leading banana germplasm improvement programs. TR4 of Fusarium Wilt (aka Panama Disease) is so far confined to the old world tropics, but once it makes the leap to the new world the Cavendish and Gran Naine plantations are quite likely to be wiped out, just as Gros Michel was before them by TR1. It's not the end of bananas, though, it's just the end of bananas as North American consumers know them. There are numerous cultivars that are proving at least resistant to TR4, and the various banana improvement programs (ie the FHIA, as mentioned above, as well as the INIBAP programs and the African and Brazilian labs, whose names I do not immediately recall) are all working to build a "better" or at least more resistant banana.
