Assembling an FPGA board on 2 layers PCB

the idea of haveing gnd on bottom, vccint as recangular underneath the fpga and vccio as well as the fan out of the traces on top layer is not new. cyclone 3 also required a third voltage 2,5v. for cyclone 2 this can be done on 2 layer but you can not control the impedance |Z| of your power supply as you have not enough planar capacitance what you only get with solid wide areas that are very close together 50-60um and not 1,5-1.6mm apart on a 2 layer. (image a capacitor with 2 plates very close together)