Yes the upgrade will be worth it - the LGA1155 / i5's are brilliant chips that have a very good work rate per clock cycle.
The only potential problem you will have is the GPU - though this will largely depend on what gamnes you play and if you overclock the nerw CPU.
Well, I'm willing to sell my cuurrent HD5770 and getting something more powerful but i'm currently focusing on upgrading my Cpu and Mobo before invy bridge comes around as prices here in my currently degrades fast especially used stuff
have you considered keeping everything else as it is and upgrading the monitor and GPU?
i'm considering that after getting the previous Mobo and cpu and saving up some money
for gamming you select right cpu that is INTEL I5 2500K this cpu is strongly recommended for all types of games with nvidia gtx 580 your games will be run in maximum setting and max resulotion but resolution depend on moniter and games depend on gpu.as i stated that gpu for gammin g is nvidia gtx 580 or 6950 both are fit but gtx 580 is better.
many thanks m8 and u are right both 6950 and gtx 580 are Epics!!
i think u all agree on me buying an i5
many thanks to all
and sorry for my bad English
if u have any more thoughts please don't hesitate telling them