I think that for many futurists the default vision of social existence a century hence is one of expanded rights (poly marriage, human-robot romance, that sort of thing), acceptance of cultural experimentation, and the dominance of the leisure society (robots doing all of the work, humans get to play/make art/take drugs/have sex). Call it the "Burning Man Future." With sufficiently-advanced biotech, people can alter or invent genders & genital arrangements (think KSR's 2312); with sufficiently-advanced infotech, people can run instant simulations of social and personal evolution (think the last chapter or two of Stross' Accelerando); with sufficiently-advanced robo/nanotech, class and work-related identities are of dwindling or no importance. Social divisions likely to still be around are those around politics (power still matters), art (aesthetics still matters), and the legitimacy of choices (the Mac/PC religious war writ large).
A more nuanced version of the Burning Man Future would allow for the establishment of sub-communities with radically different norms, able to isolate themselves either physically or informationally. Systems of abundance mean that any kind of social configuration is at least plausibly sustainable, while the kinds of interfaces we'd be using (engineered/upgraded brains, etc.) would mean that any level of filtering or reality manipulation is possible, too. Imagine a city street where not one of the hundred people around you sees the same version of reality, the interface systems translating the physical and social environment into something interesting and/or culturally acceptable. (This would also be a remarkable tool for mind control in a totalitarian regime.)
The more extreme version of that would be one where all experiences are market-driven, where everything (including hearing music playing in a building or the appearance of a designer outfit) would require a micro-transaction to hear or observe.
There's also the question of how pervasive Gossip/Reputation Networks will be; my gut sense is that they'll be all over the place by mid-century, but seen as ridiculous and dated by the early 21st.
That raises a larger point: it's not just that by 2113 we'll have gone through another three or four human generations (depending on how you count them), by 2113 we'll have gone through a dozen or so technosocial-fashion generations. Smartphones give way to tablets to phablets to wearables to implantables to swallowables to replaceable eyeballs to neo-sinus body-nanofab systems (using mucous as a raw material) to brainwebs to body-rentals... and those are increasingly considered "so 2110." And with all of these (or whatever really emerges), there are shifting behavioral norms. Don't look at your phone at the dinner table. Don't replace your eyeball in public. Don't reboot your neo-sinus in church.
At the same time, many of the Big Socio-cultural Fights we're having now will seem as ridiculous in 2050 as the cultural angst in the 1960s over hair length, or the performance of an expressionist orchestral concert in 1913 leading to a riot in Vienna. Gay? Bi? Trans? Cis? What does it even matter? What *really* pisses people off these days is the use of real meat instead of fleshfabbers... Barbarians.
All of this strikes me as plausible assuming that we don't run into major catastrophic downturns, which tend to push us towards more tribal behaviors and demand strict adherence to norms (where threatening community stability also threatens community survival). So there's your choice: Burning Man or Walking Dead.
[And that's the extent of my "Walking Dead" reference, btw. No zombies here. ]