Spider-Man has joined the Fantastic Four. Actually, he's joined something called "The Future Foundation." One member of the Fantastic Four, Johnny Storm AKA the Human Torch, was recently “rebooted to the curb.” And, although the Fantastic Four is no longer calling itself "the Fantastic Four," they still needed "a fourth.” Hence, the inclusion of Spider-Man.
There are a number of disturbing aspects of this story. It is one of cynicism, corporatism, and psychosexual braggadocio.
What is the significance of the strange symbols on the Future Foundation's outfits? You can of course find out by reading the whole thing here.