Intel's i3 is a dual core, while the i5 is quad core. If all you're doing is the things listed, then the SB system will be fine... however, when IVB drops, the SB line may be cheaper??? That I'm not sure of, but it's possible.
right now ivy bridge is non-existent but it promises quite a lot - stronger igp, configurable tdp, higher clock speed, better ultrabooks, native pcie 3.0, usb 3.0 support, sorta thunderbolt support, more sata iii ports and so on. But, it is still untested, unreviewed so all the info is based on news and assumptions.
remember the greatness of sandy bridge cpu launch and the subsequent cougar point biznes. remember how bulldozer performed after all the hype and expectations.(i skipped how llano performed because i like llano more than i like bulldozer)
right now sandy bridge is tested, worked out, working.
And after Ivy there will be even better Haswell... If Intel does not screw up... but I don't think so...
So there is allways better coming guite soon... Think what you need and just grap it when you need it.
I am going to build new HTPC and I am not in hurry, so IVY would provide even better CPU for that purpose... I know that I want to have desent GPU power and very low power usage. IVY GPU is not too good, but it is better than Sandy version (a little bit) and it should be good enough for HTPC use... if Intel can get their drivers right... *sigh* Most propably I have to buy GPU from AMD or Nvidia in anyway...
Since the fabrication die size is reduced to 22nm you can expect higher clock speeds. There are minor tweaks that should make the CPU core a little more efficient. Meaning at the same clock speed, Ivy Bridge should be a little faster than Sandy Bridge. Probably an increase of 6%, but we will have to wait for benchmarks next year.
The biggest improvement will be the integrated graphics core. Ivy Bridge's IGP performance is expected to be about 60% better than the current Intel HD 3000; at least that is Anandtech's early estimate. The Intel HD 3000 is marginally better than the desktop Radeon HD 5450. The means Ivy Bridge's IGP performance will probably be halfway between the desktop Radeon HD 5550 and HD 5570.
1. q1 2012, around march-may
2. core i5 has turbo boost, slightly higher clock speed, higher igp turbo boost, higher power consumption, faster performance. core i3 has no aes-ni(the desktop ver.), no cpu turbo.