MacRumors is reporting that it has heard from reliable sources about the heavily rumoured ultra-portable Mac/sub-notebook.

The site which is historically accurate notes that the ultra-portable Mac is due at this months Macworld Expo which kicks off on Tuesday 15th.

MacRumors sources stated that Apple has significantly reduced the size of the ultra-portable by removing the optical media drive, a drive will instead be supplied for use externally.

Although unable to confirm whether this is referring to the ultra-portable or another notebook revision which is also expected at Macworld, the rumour site notes of a so-called multi-touch trackpad.

In September 2007, 9to5Mac reported on a slim aluminium MacBook which had “something strange about the touchpad.”