Picasa Web Albums being hidden in Google search results

I was doing some searches in the main Google search when I noticed that it's now apparently got much harder to find Picasa Web Albums in the search results.

I wrote quite extensively about searching Picasa Web Albums on Google before and at the time the search results were reporting around 30,000 results (and I saw higher figures after that). However, today the same search I did then, site:picasaweb.google.com, claims just 3340 results, and shows just 1 (the main Picasaweb page), together with the message

In order to show you the most relevant results, we have omitted some entries very similar to the 1 already displayed.
If you like, you can repeat the search with the omitted results included.

If I search for the same "popular" words that I looked at before (photo, picasa, here...) then the reported number of each of those seems to have mostly stayed the same or maybe increased slightly.  Thus these results are compatible with a fairly straightforward algorithm change - one that spots that Picasa Web URLs are pretty similar to each other, so collapses them all as "omitted results".  The change in numbers would seem to indicate a more accurate number is being reported - though an order of magnitude change brings new extremes to the definition of the word "about" that always precedes the counts on Google's result pages.

Googlified is reporting a similar number of results to me, so I don't think this is just a blip in one of the datacentres.

Update: MSN also shows about 3000 URLs pointing at Picasa Web Albums, so this looks to be a fairly accurate figure, and an indication that the previous 30000 was very inaccurate.