Over the last year, Google has switched from the "host crowding" method of displaying multiple results to the same site, to a system of displaying all those results on SERPs.
eg: Host Crowding was the old method of:
--- indented 2nd site result
The new system displays all the results inline. In many cases, up to ten results can be for the same site.
The result has been (for many of us), a frustrating - if not - fatal loss of Google search relevance. The only way many of us have gotten around it, is to become very good friends with the minus operator "-" (which has also quite working at times) to remove the site from the results.
Google has not talked about this change much at all. Despite numerous people talking about the loss of relevance with the new system, Google has continued to turn up this dial.
For me, the new system has all but been a nail in the coffin of my Google usage. I can't recall a SINGLE time other than a navigation query, that I have EVER clicked on a result from a site showing 4 or more results from the same site. I had been using Google for about 20-40% of my queries (always starting at Bing) - which was actually a pretty good track record for Google if you consider that means Bing was failing for me 20-40% of the time.
The only real new thing here is that for the first time, Matt Cutts talks about the issue in a video, but never does in fact answer the question entirely. I have yet to hear any major voice say this is a plus.
Matt gives quite a few comments about whey host crowding is a plus. In fact - listen close - seems almost as if he prefers the old method like all of us do...