Ok, let's see what all we have now:
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 confused (?); -- upd.:
bradfitz and
abates deem that SEs'll be less confused... eventually. ;-)
4) Users using proxy servers following RFCs which have forbidden "_" in DNS names get even more "fun". -- upd.: Nope, nope. I was mislead to this conclusion by a post made in some community I read. 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.
+ upd.:
5)
vampwillow: "
The LJ favicon fails to work ...." --
bradfitz: "
Give us a day."
6) Users' habits get crumbled (
discussion);
7)
giant_moose: "
OpenID auth is broken, too" --
bradfitz: "A fix is checked in to cvs, but it can't go live until at least tomorrow".--
bradfitz: "
Fixes are live on the site now."
8)
sub_divided noticed
wrong redirection when trying to access a community's tag list.Thank you for your answers, corrections, explanations and additions!