The raspberry pi is absolutely not the cool thing about this set up[1]. The cool thing is that in 12 months you can switch out your SOC for a better one.
1. The pi is good because it has a large community and GPIO pins, it's a terrible choice for a 'PC' device today-- it's pretty much the weakest CPU you can get in the ARM/SOC world, with an out of date instruction set (v6 vs v7). You'd be much better off going with a beaglebone black or MK802, at the low end, with a world of more powerful options.
I have a budget (£99) Android phone from Samsung, non-contract (pay as you go/"pre-paid"). It has an 800MHz processor and web browsing on it is great. I have a Raspberry Pi, it has a 700MHz processor. The web browsing experience with more than one tab is awful. It can barely handle 2.
1. The pi is good because it has a large community and GPIO pins, it's a terrible choice for a 'PC' device today-- it's pretty much the weakest CPU you can get in the ARM/SOC world, with an out of date instruction set (v6 vs v7). You'd be much better off going with a beaglebone black or MK802, at the low end, with a world of more powerful options.