The new 80GB Microsoft Zune MP3 player has sold out across the web in the US. The first generation 30GB player was by all accounts a miserable failure, but the updated snazzy Zune has been kicking ass across the US.

The Zune has been seen as a bit of a joke by most people. The idea that it was touted as an 'iPod killer' made the naysayers even happier when no one bought one.

But now a recent price cut to the original model, and the launch of the Zune 2 range, have seen popularity unexpectedly skyrocket.

The much-maligned 30GB brown Zune, which launched last year, has been sitting pretty at the top of the Amazon US MP3 player chart for a couple of weeks now. And sales of the new 80GB 'Zune 80' models have curtailed only because stocks have now completely sold out.

Zune boots iPod

So how has the Zune made such a comeback? One stroke of genius on Microsoft's part was to update all of the old Zune models to the new version 2.0 firmware. The new Zunes come with an improved operating system and the first-gen Zunes can be updated to run this new software.

"The new UI is a vast improvement over the old version," says blogger and Media Center MVP Ian Dixon, who owns a 1.0 Zune. "It looks like a complete rewrite... the v1 software was basically a customized version of Windows Media Player."

The updated firmware is not only keeping existing Zune owners happy, but it has also reignited sales of the original Zune model online. Swing by eBay and you can pick up a first-gen Zune for under $100.

And all the while, the new Microsoft Zune players have been getting rave reviews all over the web. It seems that the bad reputation is fading. And the Zune is now seen by many people as a serious alternative to the all-powerful Apple iPod.

So, is the Microsoft Zune a potential iPod killer? The answer is no (obviously). But the Zune is certainly now a serious 'best of the rest' contender. And the likes of SanDisk and Creative will no-doubt be slightly worried about what has been, in all honesty, one of the biggest tech turnarounds in recent years.