gravity - Will Saturn's rings become a moon?

The currently leading answer is correct to say that moon formation inside the Roche limit is unlikely.

However, the disk is evolving due to viscosity between the particles, and as a consequence it "spreads", so that material is able to move to outside the Roche limit.

In fact this is a leading possible explanation for the formation of the inner moons of Saturn - that an initially much more massive ring system underwent viscous evolution and spreading, and that material spread outside the Roche limit was able to condense into the inner moons. See for example http://arxiv.org/abs/1109.3360

Whether such a process can continue is doubtful. Models for viscous disk evolution show that the initial evolution is very rapid and that subsequent evolution is very much slower, so that the rate of mass transferral to outside the Roche limit is now quite small. It maybe that it is too slow to form anything new and that any mass would be just accreted onto existing Saturnian satellites.