Tomorrow, the League of Legends ranked queues will be disabled in preparation for patch 4.4, presumably arriving sometime this week. Over on the League of Legends forums, "Riot Zaps" gave us the heads up.
"On [March 18], starting at 1:30 AM PDT, ranked queues will be disabled in preparation for patch 4.4. At 3:00 AM PDT, the servers will be shut down and all games currently in progress will end in a draw and stats will not be recorded. We estimate the battlegrounds will be unavailable for 6 hours."
While I've yet to see patch notes, Riot earlier this month proposed a few changes to Lich Bane. A few minor tweaks to Fizz, Diana, Twisted Fate, and Ezreal were also talked about. It's unclear if tomorrow's downtime will result in the release of patch 4.4, or if that is coming later on, but we'll keep you updated.