Mac client possibly coming as well
[Update: As noted by GameSpot, Riot Games has since come out to confirm that the offline mode for League of Legends won't be playable from home or LAN centers. VP of eSports Dustin Beck said that "We built an offline solution for the Finals for the pros to be protected from internet connectivity issues."]
These past few weeks must have been particularly hectic for Riot Games. Despite some technical problems, the League of Legends season two World Playoffs continued after a delay, and now we are all set for the Finals this weekend. Here's hoping that everything goes smoothly.
At a Q&A session, Riot CEO Brandon Beck said that a LAN (i.e., "offline") version of the immensely popular MOBA is in the works for hosting tournaments and should be used tomorrow at the big event. It's unclear if such a client will ever release to the public.
Regarding a possible Mac client for League of Legends, Riot said during the Q&A that "We'll have some news soon on that front."