Something that is not clear to me is how the iPhone native testing would happen. Is selenium webdriver also capable of driving an iOS native app?

You can use Apples own UIAutomation tests for that: http://answers.oreilly.com/topic/1646-how-to-use-uiautomatio...

You can, using Frank. https://github.com/moredip/Frank

It uses cucumber to drive the tests. It's still kind off experimental, but it's starting to become pretty good.

another option is Kif (https://github.com/square/kif) an iOS integration/UI testing tool developed by Square.

we've had some good experiences thus far testing some of our newer iOS projects with Kif

I think the answer's a clear no, and he just skirts around that issue. OTOH, I could see setting something up on the simulator and testing using a desktop testing framework.

ovi256 there are lots of options for testing native iPhone/iPad apps on both the simulator and actual device

For web testing, I highly recommend watir. Selenium couldn't handle modal dialogs well enough for me and watij kept crashing. Watir's been able to handle anything I've thrown at it so far.

No FoneMonkey? http://www.gorillalogic.com/fonemonkey