UPDATE: Apple still hasn’t dished up its MacBook nano, but web records show there could be an update to the MacBook Air on the way, oh and this gorgeous Apple Netbook concept has popped up too. Feast your eyes on its folding beauty!

Apple’s Macworld expo will kick off on Monday, with Mac fans eagerly waiting to see what Phil Schiller unveils the next day. Steve Jobs might not be present, but we reckon we know what the star of the show will be. Apple’s long-awaited ultra-portable. The MacBook nano.

Feast your eyes on these mock-ups and you’ll get a feel for what Apple could have in store. We’re talking about a Mac small enough to slip into any bag or purse, but with enough power to kick the Asus Eee, MSI Wind and even Sony’s Vaio netbook right where it hurts.

How will Apple manage it? By doing what its designers do best: stripping away the features that clog up other ultra-portables, leaving the MacBook nano with more space to cram in the kit that really matters.

We reckon an Apple-branded netbook would shun connectors for external monitors, wired network connections and even abandon hardware support for headphones and a microphone. After all, if you’re using an ultra-portable you’re unlikely to be near an external monitor, and built-in Wi-Fi and Bluetooth can handle everything else.

What’s more, we reckon there’d only be one USB socket, alongside Apple’s trusty MagSafe power connector, and there’d be no worrying about whether your 3G dongle will fit, because Apple’s designers will also build in a SIM card slot, using everything they’ve learned from the creation of the iPhone to let the MacBook nano hop online through mobile phone networks.

Apple could even pair up with existing iPhone carriers to sell the laptop alongside the handset in their stores. All the software is already written, and proven on the iPhone, OS X Leopard quietly introduced stereo Bluetooth support, but has yet to put it to any serious use, and Steve Jobs has already stated his team has “interesting ideas” for a netbook.

It’s the perfect replacement for the 12 inch PowerBook, discontinued in May 2006, and could be cheap enough to stave off the effects of the credit crunch. Jobs and Co have been chanting that companies should “innovate out of a recession” for months. Could this be Apple putting that preaching into practice?

Take a look at our mock-ups below. We think you’ll agree it’s a tempting prospect. We’ll know for sure whether Apple can pull it off on Tuesday.

TBC | £TBC | Apple