Its possible, but i heard there was no multi-tasking at all.
Those familiar with the design of iPhone 4.0 said that the user interface will resemble Apple's desktop Expose feature, in that a key combination -- reportedly hitting the Home button twice -- will trigger an expose-like interface that brings up a series of icons representing the currently running apps, allowing users to quickly select the one they want to switch to directly. When a selection is made, the iPhone OS zooms out of the Expose task manager and transitions to that app.