What we at Emcraft Systems see more and more is that WiFi connectivity is becoming a must-have requirement for many microcontroller applications. I would say that about 50% of our customers require it immediatelly, and the figure would probably grow to be perhaps as high as 75% if I count in people who plan on having it in a next generation product.
For those who interested in getting WiFi connectivity with the Kinetis MCUs, read through the link below for a discussion on how off-the-shelf USB WiFi modules could be used to get WiFi on the Kinetis K70 / K61 running Linux (uClinux). One interesting thing about the Linux solution is that it provides the WiFi access point (AP) functionality, allowing other wireless devices, such as a notebook or smarthpone, to connect to the K70 using WiFi without any additional equipment. Great feature if you need to be able to access a standalone device.