There's a famous quote from Steve Jobs about shipping a stylus
with an iPad: 1
It's like we said on the iPad, if you see a stylus, they blew it. In multitasking, if you see a task manager... they blew it. Users shouldn't ever have to think about it.
Which is why I doubt you'll see a stylus ever ship with an iPad. It's another
thing you'd have to manage and remember to bring with you to use your iPad and that's definitely not the Apple way.
That said, there's some apps that clearly would be made better with some other form of input than your fingertip and there's a lot of different stylus options 3rd party companies have produced.
But if you're going to buy one iPad stylus, you should buy the
Cosmonaut from Studio Neat. It sells for $25 + $7 for shipping international. You can read Marco's review of the Cosmonaut if you need more convincing ( Spoiler: He loves it.)
Studio Neat is the same guys that made the sweet
Glif iPhone adapter that allows you to mount your iPhone on any standard camera mount. I have one and it works great, particularly if you want to use your iPhone for any video recording. Pick up the Glif and the Cosmonaut and you'll get free shipping.
While you're waiting for your order, check out
the video detailing how the Cosmonaut is made featuring with an introduction by Mr. Rogers.