Well, to answer your first question -- yes, there are some users who like the redesign. It's a bit of an echo chamber in the comments, but we've received some complimentary emails. (Which is not to say we weight those more heavily than uncomplimentary ones -- we don't.)
Commenting is certainly not an afterthought. It's at the top of our list for things that need more work. We know you come to the site for the comments (as we ourselves did back in the '90s).
"as we ourselves did back in the '90s" - interesting choice of words. Are you implying (either on purpose or by accident) that you don't come to the site for the comments anymore, or that you just don't come to the site (except for work)? Why?
The beta looks terribly cookie-cutter in its design, and the comment layout just feels off. It doesn't feel right. Sorry, but I'm not sure how else to explain myself in this case. But do keep in mind that Slashdot is Slashdot because of the users that participate in the comment sections (AC or not), not because of the stories posted. Experienced users know how to wade through the piles of shit posts (frosty piss, update your hosts file, you're a friend and a cosmonaut, etc) to get to the real discussions. Rather than overhauling the entire site, why not make it easier on newcomers to get to "good" comments and participate in a real discussion? Figure that out first and I think other needed improvements will become obvious.