Out of SFO, using JL will land you at HND instead of NRT now. It has its pros and cons; HND is in the heart of Tokyo, but it lands at night. If you've been used to NRT before it'll be a whole new experience flying into HND. Very little time to be confused (not that it's difficult anyway as signs are easy to understand) as the monorail and trains stop running just past midnight which isn't much time after clearing immigration, baggage claim, and customs.
Furthermore, many flights land at the same time so the immigration, baggage claim, and customs tend to be very chaotic. At least that's how it was when I landed at HND mere five days after its opening; they may have gotten better now in handling this considering Japanese efficiency. But come January, even more flights like AA's JFK-HND, AC's YVR-HND, and BA's LHR-HND will land around the same time so you betcha it's gonna be much more hectic and hustle-and-bustle than it is right now.
On the plus side, a lot flights are being added to fly out of HND as well so it's much closer to leave HND than schlep all the way to NRT.