Whoop! Whoop! Onshape just announced in-context assembly capabilities on their forum.
This is HUGE for any design I've ever done - tips Onshape over the edge to production ready software. The way they've implemented will make a SolidWorks user weep (I did). Posted a write-up about it here:
Wait, where did my brain go? Oh, it's in a puddle here in my lap.
I read the post from the Twitter link and watched the video. I want to go on a table flipping spree while screaming like a deranged madman. My soul now screams for release from Solidworks.