I actually am partial to that idea but you know as well as I do that “a proliferation of universes” is not part of standard cosmology, and Guth says so himself, even though he, like Linde, Greene and others are also partial to the concept of “eternal inflation”. But inflation itself is still (sadly) lacking the polarizations to finally verify it. I’m hoping the newer telescopes will fix that.
"Guth's inflationary theory predicted."
Inflation is part of the standard cosmology. Guth's "multiverse" is just a model for inflation.
In the first 10-34 seconds or so of the universe's history, it underwent a brief period of extremely fast expansion, known as inflation. This period smoothed out the universe's original lumpiness and left it with the homogeneity and isotropy we see today. Quantum mechanical fluctuations during this process were imprinted on the universe as density fluctuations, which later seeded the formation of structure.
http://cosmology.berkeley.edu/Education/CosmologyEssays/The_Standard_Cosmology.html