Market research from US stats gatherer ChangeWave suggests Apple fans may be delaying laptop purchases just in case the much-rumoured iPad tablet shows up.

Earlier this month, ChangeWave asked 3314 consumers about their recent and anticipated buying habits.

Together, 18 per cent of respondents said they were very or somewhat likely to buy the Apple tablet, so there's clearly interest there. Three-quarters of them said they'd pay $500 or more for an iPad, though only 37 per cent were willing to pay more than $700. Some pundits have said they expect Apple to charge $999 for it.

ChangeWave said the degree of interest in the putative tablet matches exactly the demand it measured back in 2005 when Apple announced it would transition the Mac family from PowerPC to Intel processors.

The two cases - the evolution of an established platform that punters know, and the creation of an almost entirely new one that they don't - may not be directly comparable, but ChangeWave's point is that the level of interest shown in Intel Macs was born out in subsequent sales. Surely, then, the same degree of interest in the tablet bodes well for the new platform too.

In August 2005, 37 per cent of potential Mac buyers said they would briefly delay their purchases to wait for the then new Intel-based machines.

In January 2010, Apple's share of ChangeWave survey respondents who bought a laptop in the past 90 days dropped to 17 per cent from 24 per cent in October 2009 and 25 per cent in September 2009.

Dell's share, by contrast, was 18 per cent, up from 17 per cent in October, though that was down on September's 24 per cent. HP has been on the rise since September, with shares of 21 per cent for that month, 25 per cent for October and 29 per cent for January 2010.

ChangeWave puts the PC companies' more recent increases down to the debut of Windows 7, a key factor in Apple's recent decline. But neither firm's gain was the same size as Apple's drop, suggesting other factors may be at play. There has been so much Apple tablet speculation over the past few months that it's hard to conclude this hasn't had an impact too. Particularly since Apple's desktop share, despite Windows 7, has increased, to 20 per cent from 17 per cent. ®