Portable Apple devices of all stripes get a unifying iOS 4.2 update today, bringing multitasking, AirPlay and other improvements to the iPad. Apple said the go-live date is by 10am Pacific time (5am AEDT), but some sites are already reporting iTunes updates.
There's also disabled-but-still-accessible wireless AirPrint powers, which you can bring back through a manual workaround or an automated hack app — or a more elegant, hack-free app like Printopia. For a full take on what 4.2 does for the iPad, read Gizmodo's take on how there's "no going back".
Most notable for iPhone users in the 4.2 update is the announcement of newly free Find My iPhone capabilities. Apple's effective phone tracking and remote lock/wipe utility previously required a $119-per-year MobileMe subscription, but now everyone can rest a smidge easier that nobody who finds their phone in a cab or restaurant can get too far into your iOS life.
iOS 4.2 is a free download for iPhones, iPod touch devices and iPads. As per usual, Apple's servers will likely be overwhelmed this morning, so check back occasionally if you get no response.