Considering the depths that Apple fans will plump into a new version of iOS even before it’s released — let alone a month later — we’re amazed to hear that developers are still stumbling upon new features of iOS 4.2… especially when those features are as buzzworthy as augmented reality. Yet that’s just what Occipital has discovered lurking in the firmware of Apple’s latest iteration of its popular mobile operating system.

There’s already a few hacks out there to allow you to extend the admittedly rather limited AirPlay functionality of iOS 4.2 to run on non-iOS devices: last week, for example, TUAW’s Erica Sadun released AirPlayer, an app that tricks AirPlayer into think your Mac’s an AppleTV.

Now, though, plucky and ingenious hackers are figuring out how to do the same thing on non-Apple hardware, and the first fruit of those labors has now been released for Linux.

With every major new release of iOS comes a period of anticipation for the next release of a stable jailbreak courtesy of the iPhone Dev Team… and the good news this time around is that it doesn’t look like iOS 4.2.1 set the Dev Team back very far at all.

One of the most frustrating aspects of iOS 4.2 and OS X 10.6.5 is how Apple’s new wireless printing standard, AirPrint, was gimped at the last minute from running on pretty much every shared network printer connected to a Mac to only officially supported on 11 AirPrint-compatible printers.

One iPad owner named Stan was so frustrated, in fact, that he wrote to Steve Jobs. “You got me all hyped about AirPrint. Now with iOS 4.2 released, I find out that I can only print on 11 select printers. Seriously?!”

Seriously, replies Steve, before reassuring Stan that the move to driverless, wireless printing is a vast undertaking, and that iOS 4.2’s AirPrint support is only the first step.

It’s been well over six months since we last heard that Apple might be considering dropping its MobileMe subscription fee, but newly discovered code in the iOS 4.2 and 4.2.1 gold master builds suggest that Apple hasn’t scrapped plans for MobileFree: in fact, it could launch imminently.

Apple has just released another gold master candidate of its long-awaited iOS 4.2 firmware to developers. This version is iOS 4.2.1, and we assume it quashes the Wi-Fi bug that’s recently been affecting the iPad.

MacRumors reports that Apple has instructed developers not to resubmit their applications under the new build, suggesting that only minor fixes are included in this update.

Unfortunately it’s not the iOS 4.2 news many of us have been anticipating, however, it’s nice to see Apple are fixing these bugs before they release the firmware to the public.

Developers can get their hands on iOS 4.2.1 via the iOS Dev Centre.

Last week’s great disappointment was the discovery that Apple had mostly pulled AirPrint support from OS X 10.6.5, which would allow you to print documents directly from iOS to almost any shared network printer. Native AirPrint support was trimmed only to a small number of AirPrint-compatible HP printers, and while hacks exist to get AirPrint support back via the command line, they’re a little beyond the capability of most users.

Enter FingerPrint, a new application from Collobos Software that enables AirPrint printing over Bonjour for many of the omitted printers. It accomplishes its neat trick by fooling Bonjour into broadcasting your normal printer in such a way that iOS 4.2 can see it.

We reported on Friday that a nasty WiFi bug causing random drops in the gold master build of iOS 4.2 was likely to delay release of the update from anywhere between a few days to the end of the month.

It looks like that report was right: Apple has just dropped a second GM build of iOS 4.2 for the iPad, updating the GM from 8C134 to 8C134b.

Where this puts the official release of iOS 4.2 is anyone’s guess. We’ve previously heard rumors to expect iOS 4.2 to drop tomorrow, but some sources are placing the official release date as far away as November 24th.

Ultimately, what it will all come down to is how much testing Apple thinks the new GM will require for a fix to a single WiFi bug. Taking all bets!

In the meantime, you can download the second GM for developers here.

One thing’s for sure: iOS 4 hasn’t been very kind to iPhone 3G owners. Not only did the major update end up slowing most iPhone 3G devices to a crawl once installed, but iOS 4.x under the iPhone 3G is missing many of the features like multitasking or GameCenter that other devices get to enjoy.

The good news for iPhone 3G users is that the soon-to-be-released iOS 4.2 update supposedly does a lot to improve the 3G’s sluggishness problems. The bad? Apple’s culling yet another promised feature from 3G owners: AirPlay isn’t coming to the iPhone 3G after all.

I hope you didn’t jump out of bed at the crack of dawn today, throw open the curtains, crack open a few eggs in the frying pan, connect your iPad to iTunes and then sit down to spend the next few hours to continuously hammer the “Check for Update” button, because we’ve got some bad news for you: it doesn’t look like iOS 4.2 is going to drop today.