It looks like the FileVault issue that hit the news a couple of days back is addressed in this update. Also, they released a Security Update for 10.6.8 clients, but its hard to tell what it addresses. All the links for info on it seem to point to a generic "Apple Security Update" page. Way to go on being obscure Apple :/
I am currently downloading a new Lion Installer application which lists itself as 10.7.4 in the Mac App Store.
It did not show up in the Updates tab, I had to go to Purchases and manually trigger the download.
Dunno just yet about the expired certs. I'll try compiling an image and get back to ya. ;)
Haha, if the certs are still expired on a new 10.7.4 download from the App Store, I will personally get up from my desk, drive to the nearest Apple retail Store and slap the first Apple employee upside the head I see! (even though they would have had nothing to do with it). :-D