Apple's notebook lines look set to spearhead the Mac maker's shift to Intel processors next year, with the launch of updated PowerBooks and iBooks coming in the Q1/Q2 2006 timeframe.

So claimed "extremely reliable sources", cited by AppleInsider, though the report is short on detail.

Updated PowerBooks are likely to be announced first. Expect a new 15in widescreen model first, based to an extent on the current design but with much-reduced thickness. The new 15in PowerBook is said to be 20-25 per cent thinner than the one you can buy today. That takes it down from 2.8cm to between 2.1 and 2.2cm.

The sources claim the updated 17in widescreen PowerBook will appear a few months later. Alas, the report reckons there will be no replacements for the compact and Register-favoured 12in PowerBook G4.

One ray of light is the anticipated widescreen iBook, which has been rumoured to be in the pipeline since April 2005, when Taiwanese contract manufacturer sources said Apple had been out looking for a partner to produce the machine.

If AppleInsider's sources are correct, it will be an Intel-based job, shipping in time for the April/May US education market buying spree, and equipped with a 13in widescreen display. The sources suggest - though it's no great leap of the imagination given the recent iMac update - that the new iBook will incorporate a web cam. The new PowerBooks may well do so too.

Apple announced in June 2005 that it would move to Intel processors from PowerPC technology during 2006, with the first machines due on the market by June 2006 and the range completely ported over by the end of 2007.

On the notebook side, Intel's upcoming 'Yonah', not only its first 65nm notebook-oriented processor but also its first dual-core laptop chip, is due to begin shipping late 2005 with a formal debut in Q1 2006, which puts it within the timeframe suggested by AppleInsider's sources.

Reports last week suggested versions of Mac OS X for Intel and for PowerPC processors are both at parity, suggesting Apple is ready to ship the Intel release when it feels the time is right. ®