I read about this a few days ago on The Register, according to one user there, this particular issue is to do with DKIM and mailing lists (the stuff Linus had issues with was all Linux kernel mailing list messages);
bhtooefr "Basically, Google's enforcing DKIM from certain domains, and if a message is "from" someone whose e-mail host provides proper DKIM, but it's missing it, Google (and Yahoo) servers reject it. Mailing lists aren't usually set up to properly handle DKIM (being, effectively, a relay), and therefore get rejected.
The workaround that I saw one mailing list use was to resend the e-mail from the mailing list's address, append "via (mailing list name)" to the name on the from field, and just have both the mailing list and the original author in reply-to."
Seems like people running mailing lists need to take a look at how spam filters work, rather than mail providers changing anything. If I understand correctly, the policy is sensible and blocks a likely spam vector, and legit mailing lists could easily be set up to not fail that particular check.
For regular mail, I'm like you guys, Google's spam filtering does a fantastic job. I never check my spam folder any more, unless I'm expecting an email and it doesn't arrive, but it's been ages since I had a false positive.