Steve Jobs' idea of iPad was to build a tablet that did not need a stylus or any physical device to operate it. But now seems like Apple will go ahead with idea of making a stylus for the iPad to perform certain tasks.
Apple has filed a patent for a stylus which is a bit different than the normal stylus offered for tablets. The Input Device Having Extendable Nib is what they will be developing for the iPad if their tests succeed.
The nib on the stylus will not be just a standard capacitive nib. The stylus will have an actuator(a handle) which will allow to move the nib from a primary to a secondary position. There are multiple positions to which the nib can be set and each position will mean a different input and different line thicknesses.
This kind of a stylus will be very helpful for artists who are involved in creative work like painting, creating illustrations and 3D models giving them the freedom to set the thickness and probably a pressure sensor. Another thing mentioned in the patent is that the nib of the stylus can be changed.
Samsung Galaxy Tabs, Microsoft Surface and other several tab makers have provided a stylus with a tablet as an input device but none of them could hit the mark. Now that Apple is entering this concept of introducing a stylus for a tablet, it could totally be a different experience using the stylus.