Developers who try to log into the iPhone dev center, the Mac dev center or iTunes Connect this afternoon are being greeted with the traditional yellow sticky note or the Sorry! note above, indicating that some sort of update effort is underway. With the on-again, off-again release of the 3.2 beta 3 version of the SDK in late February, and the unconfirmed-but-likely launch of the iPad on March 26th, no surprise that there are fixes and finish to take care of on the site.
When it comes back up, we'll let you know; if you spot anything of consequence when it does, please let us know.
Update: It's back up. The big news is on the Mac side, with the introduction of the $99 price point for ADC membership.