The other issue I have is that the "action" block is now totally disconnected from the fields it modifies, and this seems problematic--especially on bugs with more than about 5 comments. The assignee/product/resolution data is at the "top" of the page and the buttons that change those data are at the very bottom. (I'm quite fond of the comment text area moving to the bottom, though; no more scrolling up and down the page to refer to the last comment when composing a new one!)
=== Callek ===
My only comment which is not enclosed by things above, is that the individal comments text-itself, could use some more left-padding, to indent it at least a bit more than the headers for each comment, as it is those headers appear to be part of surrounding comments, rather than headers at a brief glancing. (I thought that for brief a moment).