This sentement has come up semi-frequently in the past (almost) four years I've been a member of the site, and I lurked for months prior to creating an account. From my perspective, the site has trended towards mass appeal, but not at a very quick pace. The articles on the front page today aren't all that different from the ones I remember being on there four years ago. The level of discourse ebs and flows. Sometimes it's really good; other times it isn't.
None of these things seem to be working very well. They may alleviate a portion of the pain temporarily, but the baseline level of quality throughout the community still feels way off to me compared to what I see in the old threads.
As a sidenote, I like the explanations in this post about why digg, reddit, and slashdot went sour:
I think Hacker News used to be mainly Start-Up, tech and business starters. Whereas now it is mainly start-up porn.