This is a public service announcement. If you're using Gmail, or the email built in to Google Apps, check your Spam folder. Yes, you. Right now...
And if you're the IT person for an organization that uses Google Apps email, tell your users to check their Spam folders. Senders of legitimate bulk email should also be taking action (of which, more later).
You may have gotten used to ignoring your Spam folder -- Gmail's spam filtering is probably the best in the business. I certainly know of no other cloud email service that has better spam-filter accuracy than Google's.
Many other services are significantly worse. OK, that's an unscientific statement, but it's is based on a range of end-user and IT manager reports from users of cloud email services such as Microsoft Office 365 (née BPOS), and of cloud spam filters such as Symantec.cloud (née Messagelabs).
Users of some other systems often need to grub around in the spam folder to retrieve legitimate messages that were erroneously flagged as spam by the filter -- what us spam-filtering jargonistas call false positives. Suffice to say that most Gmail users never even think about false positives, let alone check for them.
However, some time in the last day or three, Google pushed an update to its spam filter that should probably have you checking your Spam folder frequently -- at least until the company fixes the problem.