Apple can look forward to brisk sales of its new Mac OS X 10.5 'Leopard' system once it releases its newest big cat next spring.

A recent poll of Macworld UK Online readers revealed that 60 per cent of readers who voted will upgrade their OS within the first month of the software release. That's 1,340 people from a sample group of 2,214.

One third say 'upgrade fast'

Almost a third of readers plan to upgrade on the very day of release (29 per cent, 647 readers).

With Apple admitting to having 19 million active users, the statistic implies the company will sell over 5.5 million copies of its new operating system within 24-hours of shipping it, and 11.5 million copies in the first month.

The other results tell their own tale. 17 per cent (175 people) of voters plan to upgrade within three months of the release. 175 voters (8 per cent) reckon they won't upgrade until the software has been available for 3-6 months, while an additional 131 voters (6 per cent) will wait up to a year to upgrade.

A tiny proportion (8 per cent, 181 readers) of Macworld's evidently Mac-centric readership will wait over a year to upgrade, or wait until the next OS ships (48 readers, 2 per cent). Interestingly, just 4 per cent (82 readers) plan to "stick with Windows".

Will Leopard eat Vista?

Apple's previous operating system releases have been a big deal for its customers, who have camped overnight outside Apple retailers for the chance to be among the first to try the new OS.

Apple retail partners have consistently reported strong or heavy sales of the OS in the first weeks of its release. The stage seems set for similar enthusiasm when the OS ships in spring 2007.

The release seems likely to take place around the same time as Microsoft releases Windows Vista, with whatever new features it may still be equipped with at that time. One reader remarked: "I look forward to reading any objective comparisons with great interest."

"When you look at the features in this OS or even Tiger, I can't for the life of me see why anyone would still want to use Windows. It's not even a debatable topic, OS X is the most amazing OS out there. I don't get it," another remarked.

Developer chat

Some Macworld UK Online readers are also members of Apple's developer community. They can't wait to receive their copy of the new system.

"I wish I could just get the damn thing downloaded to start playing around with it! I can't get my copy yet. There's some good API changes in there and Time Machine is impressive tech, I can't wait to see how they've done that (the obvious way would be shadow files but reading further into it I can't see quite how they've arranged things). The 64 bit-ness is a bit of a 'meh' feature - they didn't really show too much of substance. The Spotlight changes look nice, almost as though it's finally classed as an application of it's own. The Finder is obviously going to be the big change but it looks like that might be a Macworld San Francisco announcement," one such reader wrote.

Cautious optimism

Others are slightly more cautious when it comes to installing a new operating system on their computer: "I have never been an early adopter of a new OS. I got 'Tiger' (Mac OS X 10.4) as it came with my new iBook. My G4 Power Mac is still running OS X 10.3.9 - although upgrading it has crossed my mind, I may well wait until Leopard's been out a while and even then I may only get it as part of a hardware upgrade," one remarked.

Other Mac users are hideously excited. They expect 2007 to be Apple's year: "Now Apple has finally switched everything to Intel and embraced the use of Windows on its hardware, I think Apple is about to go ballistic and become the Number One PC supplier worldwide. It just needs to get its message across!!! Apple Macs still seems to be the world's best kept secret somehow?"

One reader offered a sanguine voice: "It will be an important build for Intel Macs and looks very good - but I'll wait to see how much it costs and for some general feedback from first adopters."