In the comment threads, tangents, or arguments you might want to browse at -1, frequently develop. I'll open those in a new tab for later perusal so my reading of the on-topic discussion isn't interrupted. As far I can tell, in beta there's absolutely no way to do this - one discussion means you should have only one page open apparently, no matter how many facets it may contain. If you want to cross-reference between two different tangents in the same story, you have to open another tab and then click click scroll click click expand more click click scroll scroll scroll click to find the other one instead of just doing a middle-click or right-click new-tab.
The designers seem to have been drinking the kool-aid labelled "everyone uses a single fullscreen window, no-one uses tabs, there's no such thing as middle-click or right-click but everyone loves endless scrolling and jabbing the 'would you like to know more?' button". I'd wager the average slashdotter drinks from the kool-aid labelled "fuck beta".
That's one of my more minor complaints, of which I've submitted to the official feedback /dev/null^W channels. Reading between the lines, the official response is going to be "tough shit".