The next-generation iPad will be slightly thicker than its predecessor, whereas the iPhone 5 will be longer than the iPhone 4S to accomodate a larger screen, according to a report.

iLounge claims that its "most reliable source" has confirmed that Apple is planning slight changes to the build of three of its key product lines: the iPad, the iPhone and the MacBook Pro.

The next-generation iPad, iLounge's source says, will be around 0.7mm thicker in order to accomodate dual-light bars needed for a higher resolution display. The iPad 3 could be shown off in January and is on course for a March 2012 launch.

The iPhone 5, meanwhile, will get longer by about 8mm in order to accomodate a 4in screen and will have a metal casing, probably aluminium. It won't have the rumoured 'teardrop' shape, the source said, and is still in the engineering phase with a summer 2012 launch date expected. There is a possibility that an LTE chip will be included.

Meanwhile, the MacBook Pro will be overhauled in 2012, and is likely to get thinner, according to the source. We've already heard a couple of rumours about a thinner, 15in MacBook in the past few weeks.