My connection is timing out on an article I published a year ago. I edited the categories, and now it will not re-publish. Also, starting two days ago for me, another long (three Word-type document pages in length, double-spaced with gaps between paragraphs, and hey, we're talking TEXT here, times out on me every time. My connection is fast and wide (Comcast Cable Internet), so it almost has to be the server at WP's end. My guess is that since its a longer article, WP is bumping us out to reduce space requirements and allow for faster processing of other, shorter blog articles.
Yeah, that's all that makes sense to me.