[tonylemesmer]

If you've ever tried to get wifi working (esp on earlier RPis) you'll understand it is not that simple. Especially for newbies. Having said that its a good baptism of fire.

Raspberry Pi with built in wireless comms means it uses a standard piece of hardware so the software stack can be configured to work out of the box. That can't happen with the existing arrangement. Also the power supply problems with original Pis are frustrating to say the least. These are most evident when plugging in USB wifi devices. Again having a standard integrated piece of hardware will (hopefully) avoid this.

[TD-Linux]

This doesn't really reflect my experience at all with the RPi 2. The edimax or official wifi dongles "just work" with NetworkManager.

With the early RPi it was a bit different because of USB power problems and kernel bugs, but those are mostly solved.

[CaptSpify]

Experiences vary. I agree with tonylemesmer, getting them to work has not been trivial for me.