Hi
1) you can use 2014.4 board part files in 2015.1 also
2) the real release for 720 will be for 2015.2 as there is no petalinux for 2015.1
we will provide 2015.1 board files first for modules that fpga only, and can not run petalinux, TE0711, TE0741, etc
we can make 2015.1 board support for 720 also, but you must understand that you possible can not use petalinux then
but I curious, what drivers are you talking? baremetal SDK drivers?
for baremetal or non-petalinux flow 2015.1 can be used of course