I hit 350 yesterday in alchemy and nobody sells anymore recipes anywhere... the guy in Shatt doesn't have anything.. the guy in Thrallmar doesn't and so on...

Is it all world drops from here on out?

seems like you might be right, I am lvl 65, and have 375 alch/herb.  everything after 350 has either been drops or rep based vendors.

Or discoveries I'd like to add