Everywhere I go there is WiFi...

At home I have WiFi. At work I have WiFi. At any friends or family members house, they have WiFi. Most hotels and restaurants have WiFi. If I'm out and about with my iPad (rare) and I somehow need to use it online in a situation where my iPhone 4 will not do (even more rare), I just use my iPhone 4 as a personal hotspot and take advantage of my truly unlimited data plan. Feels great knowing I saved a load of cash by not bothering with an extra £100 on hardware and additional data plan each month for an iPad that simply would not get used to the full value.
Nobody in their right mind these days would have a separate data plan for portable devices other than their mobile phone.