I'm trying to decide on a Q9450 vs a E8400....
I know that the quad is more 'future proof' but I will go the nehalem in 2-3 years anyway, I don't game, OC or Video edit/ threading etc...
I will be doing the following simultaneously:
Running norton and spyware scans, surfing maybe 4/5 internet windows, downloading maybe 3/4 things at a time, possible lots of itunes on top of that and then making notes on word as I go.
This is obviously not 'hardcore multitaksing' but will the E8400 handle this better than the quad?
(I have researched threads but havent found any addressing this 'medium level mulittasking' scenario - always about gaming etc)....
The price diff b/w the two is about $130 here in Australia

That to be honest, you would be better off with the E8400 as that is not consider entirely multitasking.

If that is all you plan to do, get the cheaper of the two.

the e8400 should be more than enough for those tasks

why not just go with a q6600 if you want a quad

E7200 will do...Still I would say an overkill if you used another anti-virus... Norton hogs too much...

E8400 is more than enough

A dual will be fine. I have yet to max my e6400 even at stock settings while running so many things at once like you mentioned. It is when you are running a game, watching a hi-def movie, encoding music/video, and running a scan that a quad is going to do all of that faster. Plus, you are more limited by your hard drive(s) than your cpu in those cases. The HD would be thrashing like mad.

^ So as I said... the E7200 is sufficient