Apple continues development of a new small form-factor subnotebook and the new Mac may not ship until next year.

The rumoured subnotebook is described by various pundits as exploiting flash memory in some way: it has previously been claimed flash will be used to help boost start-up times, or as a wholesale replacement for a hard drive.

The effect of a move to flash could be a more responsive computer, low on power demands so capable of extended periods of use without access to mains power, and faster start-ups.

The subnotebook Mac would also be lighter than a hard-drive-based alternative, but flash memory prices would also mean the machines would be more expensive on a Gigabyte-per-dollar basis.

Initial reports has claimed Apple originally aimed to launch the device at this year's Worldwide Developers Conference (WWDC), AppleInsider reports.

The delay could be connected to the revised October launch point for Mac OS X 'Leopard', speculation claims.