Announced at

http://googledocs.blogspot.com/2010/06/new-google-docs-graduates.html

[title updated to make it more clear what has changedd ~ hebbet]

A little off-topic: I think they've added the version history but it hasn't been improved. I expected the better-than-Wave Time Slider from Etherpad :(http://www.youtube.com/watch?v=Endvb81oz80

Quoting shortly:

"The Google Docs team is also continually learning and we’re happy to announce that the new documents and spreadsheets editors have both graduated."