Starting yesterday, I opened up my IDE, updated PHPUnit, and got cracking. At the current rate of development a Consumer is likely at the weekend. I've already started writing up a formal proposal for PEAR and, of course, the Zend Framework also. I'm thankful the OAuth specification is this simple - it's one of the easiest to read specifications I've had to pleasure to work with.
He notes that an update to the API's Core (from 1.0 to 1.1) might be on the horizon, but can't see it affecting extensions/packages that much. He also mentions Extensions - not PHP extensions, these are augmentations to the OAuth core that allow for other different functionality to be included (like Discovery).