In some regards, this neotraditionalism is the natural conclusion of postmodernism, indeed many of these buildings, such as those at UMich and Virginia, were designed by Robert Stern, who is often said to be the "father" of postmodernism. It follows a trend that we've seen times throughout the course of history, the first being the original Greco-Roman classicism, which eventually degenerated (that being descriptive as opposed to derogatory) into Romanesque and eventually Gothic architecture. In the Renaissance we saw a snap back to the classical forms, and again we deviated to Baroque and then Rococo architectural, and then back to Regency/Empire neoclassicism (although England by and large missed out on Rococo). Again that deviated into lest purist forms and, eventually into free-form revivalism and eclecticism, until we reverted to Beaux-Arts neoclassicism once more. Then we fell into Art Deco and modernism then post-modernism, and now this... as you can see the timeframes shorten but the trend remains clear.
An interesting concept is that of a so-called "other-modernism" that encompasses a parallel trend of art development from Art Nouveau to Art Deco to the Prairie Style to Lutyensian minimalism to today, a more organic development and approach to architecture than the Bauhaus and its successors.
What traditionalism really stands for is a conservatism, not so much a political conservatism (certainly conservatives could be avant-garde architecturally- see Mussolini) but a cultural and social one. Traditionalism works. People know it, and they can relate to it. Time and time again polls show that people prefer traditionally designed buildings because they know what they're getting, because it isn't new. It isn't innovative. But this isn't a condemnation, I am excited by this trend. Innovation for innovation's sake- to simply be new- is indicative of a decadence where value is placed upon shock value. The Johnson house, for example, may be interesting to look at, but it is inconvenient to live in without destroying its form (I am imagining blinds here).
Traditionalist architecture is so popular because it stands for thing and implies them at the same time- permanence, austerity, solidity, longevity, and so forth. It implies a wisdom, rejecting the needlessly new for something tried and tested. You don't see too many modern houses, because they're uncomfortable. The idea of "home", again, is much of those same values: permanence, austerity, etc., even if most of them take the form of kitsch. Ornamentation provides a much easier derivation of value than expressions of reference that are vague at best and fraudulent at worst. Recall that proposed tower in Indonesia where the crown was meant to be indicative of several national symbols, but was found to be a regurgitation of a cancelled proposal in Nashville. The ornamentation of traditional buildings is more straightforward.
Sumptuous palaces of yesteryear may evoke ideas of elitism, but in the regard to localism they are more understandable in their design. A person could have look upon them and seen the cues which they shared with more familiar, mundane buildings- the guildhall, the church, even their home. In contrast, look at the major buildings being built today- 90% of them would be no less at home in any other major world city. Again, traditionalism is more familiar, more national.
So, in short, traditionalism is a good thing. But the great challenge moving forwards is authenticity. Many buildings here are astoundingly detailed and well-built. Others use minimalism to their advantage- one particular example being Guildford Cathedral in the UK. Many others, however, skimp on ornamentation when it is need, have incorrect proportions, or are otherwise mistaken in the use or non-use of certain elements, and look poor as a result. Hopefully technology combined with the increasing prevalence of this trend will help correct those flaws. Otherwise, I look forwards to a new traditionalism with excitement and anticipation.