Gmail users who get Microsoft PowerPoint attachments in their in-boxes can now view them without having PowerPoint installed on their machines. Google appears to have flipped the switch to allow this feature as of last night. We originally reported on this last month, although at that time it appeared that only a handful of accounts had access. This option now shows up on all accounts.
Also, somewhat related: today is the unofficial "Day without Google," a challenge that asks people to try doing their searches on alternate search engines outside of the "Big 5" which includes Google, Yahoo!, MSN, AOL, and Ask.