So DOTA sure has changed a lot...

So about a year ago my desktop got destroyed by a moving crew, and I have only just bought a computer capable of running LoL. I have been in the dark for the changes over the past year, and I have to say... Its a new game. You forget how often Riot makes new content, until you step away for a long time. I noticed that when I would put the game down for a month or two, but now Its like playing League for the first time. There's new masteries, items, and champions; old champions are reworked; and its just overwhelming.

I need help! What is the new meta?!