Based on your current rig specification, you should jump to sandy / ivy bridge + get a decent gpu (GTX660ti - HD7950). You will see a major increase in performance.
You don't need to update your hardware every time a new architecture comes out, so when haswell comes out you can still be rocking this rig for 4-5 years, just needing to update the gpu, when you want to.
Plus some of the questions you're asking are unanswerable mate, haswell isn't even finalised meaning the full specs are not out there and without information being released by intel it's impossible to say.