Yup, nothing new that'll be relevant to us will popup by then
i3 has 2 processors, but with Hyper-Threading, works with 2 Virtual cores, so it works like a 4 core CPU, not as good as a Physical 4 core though...
i5 is a proper 4 Core CPU, with Turbo-boost tech that'll make it go even faster when its running on 1-2 cores.
i7 is a beast, with 4 cores, Turbo-boost tech, AND Hyper threading, so it acts like 8 cores...
i5 is A-OK for casual gaming and working... That's what i think
