About mid lane meta

Not for 4-5 seasons, unless you're talking about Keane's Graves mid, the mostly assassin Quinn mid, or the mostly mage Corki mid.

Varus is a popular adc mid laner mostly in korea/china, but has been played a number of times in EU/NA. It's a really strong counter pick to azir who is first picked/banned in every region. NA had an ezreal mid last week as well.

If corki gets buffed enough then I'm sure he'll see mid lane play before he's played in bot lane.