I haven't really seen much talk about WHEN she would be released, but I guess it won't be any time soon depending. Seeing how long it took them to release 
(and then disabling him) I would estimate it would be in the next patch. Or maybe after SR is redone.
I don't usually keep myself updated with the news, but I am eager to try her out and sadly I am not very patient. I also feel like I am one of the few who are actually looking forward to playing Kalista.
im hyped for kalista!
My guess is Nov 25. Azir came out 3 weeks after his reveal. I'm expecting the same. Perhaps earlier if there are less bugs with Kalista.
im going to buy her as soon as she drops from 7800 to 6300. one of the benefits of having a complete account...you have always ip to spare and riot got really conservative with champion releases
There is only 1 person who actually posted about when she might come out. And my guess is Nov. 21 since it is such a special day on many accounts for many things.
let see while i was on pbe, the update for the sr on the normal server happen last patch when that happen the pbe loading screen went from vi on the front to kalista so, it may be the next patch maybe!, reason why maybe because sr is not done updating on regular servers so, it maybe 1 or 2 updates from now so ranging from nov.25 to dec. 3
also i got bored here is the next ward coming out http://puu.sh/cUaz6/5af9c0080d.jpg http://puu.sh/cRtxQ/618cca6266.jpg
I would say Kalista will be released in about 2-3 weeks mabye later due to the fact if you saw Azir they waited a bit to get the hype up after the q and a so i would just keep a close eye.
BTW: I would say that it would be more closer to 3 weeks than anything but your guess is as good as mine.
I'll probably wait several months before buying her, considering all the bugs that Azir rolled out with. Buying Azir felt like I bought a champion that was still being beta tested.
I currently hold the most IP I've ever had at once because I'm pretty hyped for her! I really enjoy how Riot strives to introduce new strategies to spice up the game. It started to feel like everything's been done already. Sure was revolutionary, but doesn't seem to fit into many places, and 
was extremely fun, but somehow got overlooked a bit. I can't wait for Kalista, her passive intrigues me.
im pretty excited to try her too actually though adc isnt my strongest role not by a long shot
