1) your (LJ's) DNS servers get more busy;
2) our DNS servers get cache increased;
-- "DNS load is the least of our problems", says bradfitz. Yes, I'd rather agree.3) Search engines get
The only thing which is left to ask is why LJ's DNS have records with "_" in name, but this don't have any relation to the URL default scheme change.-- upd.: LJ "uses" it if and only if your DNS-query contains it; there are no "underscored" DNS-records in the LJ's DNS.
5) vampwillow: "The LJ favicon fails to work ...." -- bradfitz: "Give us a day."
6) Users' habits get crumbled (discussion);
7) snej: "OpenID auth is broken, too" -- bradfitz: "A fix is checked in to cvs, but it can't go live until at least tomorrow".
8) sub_divided noticed wrong redirection when trying to access a community's tag list.
Thank you for your answers, corrections, explanations and additions!