Well, one must admit that the "base" is not very large, but after the Motu Proprio is released this Saturday, we shall see what happens.
For those that have difficulty reading bar graphs, this one says that each week in the United States, with it's 19,000 parishes, there are only 220 Masses said in Latin. It will be interesting to see what the figures will be in a few years. I'm sure the percentage will increase, but the numbers will most likely still not be very large.
Look for an bigger increase in the Latin Novus Ordo Masses than Tridentine (Pius V, John XXIII, 1962) Latin Masses.
Source: Ecclesia Dei