I've only watched the first season of Sailor Moon and a little bit of R (stupid alien filler arc) before I stopped watching.
That means you missed the best season of Sailor Moon, Sailor Moon S and the best soldier, Sailor Pluto!
But I didn't think the doom tree arc was bad, it had awesome power ups for the inner senshi and it was nice that a story was wrapped up in 13 episodes.
Here's the official western logo:
The entire announcement in english
, not much news except for a few names and the synopsis of the story, but it confirms a worldwide stream on Niconico Douga.