It looks like you'll have to wait a little bit longer to get Microsoft's usual monthly batch of "Patch Tuesday" updates. Microsoft has taken to its TechNet site (via ZDNet) to note that this months updates are delayed due to a "last minute" issue that cropped up.

Microsoft delays Patch Tuesday updates over 'last minute issue'

From Microsoft:

Our top priority is to provide the best possible experience for customers in maintaining and protecting their systems. This month, we discovered a last minute issue that could impact some customers and was not resolved in time for our planned updates today.

After considering all options, we made the decision to delay this month's updates. We apologize for any inconvenience caused by this change to the existing plan.

Microsoft has issued updates on the second Tuesday of every month like clockwork since it began the Patch Tuesday process, so this is pretty unusual. There's no word on exactly what the issue preventing the updates is, and it's unclear when we might expect them to roll out in full. We'll update this post with more should Microsoft clarify the issue.