The only thing from watching a friend play dota was that the harder you press the mouse button, the more damage you do. At least that guy practically obliterated his left mouse button while last hitting (think about somebody wanting to play a note as loud as possible on the piano... that's practically what he was doing :D).
Concerning the metagame... well, that changes all of the time anyways... Seen times centered around mass ults, getting one carry farmed, gankheavy games that are decided around the 20 minute mark, even the infamous 5 man mid push ... all of these with varying heroes in roles... dunno, no real surprises anymore I suppose. Spent the first 10-20 games or so rather lost, but after that I was in okay shape again and I haven't played any moba for ages (:
Also, Anime... TTGL is super stupid and over the top. I'm reaaaalllly loving it :D
(also I've been rather slow on anime this week and the last... only about 20 episodes
)
edit: also, I say "also" too much, but it's such a great word, that's perfectly fit for linking unrelated stuff in post