When will the Apple iPhone include a hardware keyboard?

The HTC Touch Pro2 may look like an Apple iPhone from a distance, but the minute you slide out the keyboard, you know that it's not an iPhone. HTC also has an updated version of its Touch Diamond that will look like an iPhone - slim, sleek, and no hardware keyboard.

For business users who do quite a bit of typing, it really makes sense to have a hardware keyboard. Buttons are so much easier to push than anything on a small screen. That's probably why some BlackBerry users could never imagine using the Storm (or an iPhone).

We see that Palm designed the Pre with the business user in mind. When will Apple design an iPhone that has a built-in keyboard? Will that be the next version that comes out next year? Perhaps an iPhone Pro? I think it's only a matter of time before we see something like an iPhone Pro. The big question in my mind is this: If the iPhone has a built-in keyboard (slider-version), then will the keyboard be tall and narrow (vertical), or short and wide (horizontal)?