Updated: Seems like Google was wrong, some advertisers are still experiencing issues with this tool. AdWordsAdvisor confirmed the following statement and said there is currently no ETA to a possible fix:
The support person I contacted followed up with me and told me the technical specialist they consulted confirmed the issue is still occuring for some advertisers and they are once again working to resolve it.
On November 7th we reported a major Google AdWords Diagnostic Tool Bug, where advertisers were noticing Google reporting their ads were not active, but in reality they were.
Yes, it was simply a reporting issue.
Yesterday, AdWordsAdvisor, has posted in the WebmasterWorld thread that the bug has been fixed.
I heard from the tech team yesterday - about an hour or so before Rehan's "It's fixed now" post - that the issue with the Ads Diagnostic tool had been resolved - but decided to hold off mentioning it in this forum, overnight, until I was certain.
Today, within the last hour, the tech folks have confirmed for me that all indications (other than the several 'not fixed' posts here) are that this issue is in fact resolved.
But many are still reporting that this is still an issue. AdWordsAdvisor asked those who still feel this is an issue to double check to make sure their ads are indeed live.
The tech team wondered whether it was possible that those in the 'not fixed' camp here might be misinterpreting the rejection reasons that they're legitimately seeing as further evidence of the issue. (I am nearly positive, for example that this will be the case for the "...all my keys incactive, i need to pay like 1$ to get it active, and my landing page are perfectly matched the keys" post earlier in the thread.)
Forum discussion continued at WebmasterWorld.