iMac i5 - good enough via Windows bootcamp?

I want to 5box on my new iMac. I'll be installing Windows XP via bootcamp.
Is my Mac capable of 5 boxing effectively? or would I be better off dual boxing? --have a healer follow me around
I'd be purchasing an extra Apple display. On my main character I'd like decent fps @ medium settings.

My other option is running 2 versions of WOW on my laptop and 3 on the mac (I'd need extra hardware for this)--would this be better?

What do you think? Can I run 5 instances of WOW effectively on my iMac via WINDOWS?

Specs:

27 inch 2560x1440
2.8 i5 intel Quad Core
ATI Radeon HD 5750 with 1GB
8GB 1333MHz DDR3 SDRAM
1 TB 7200 HD (only 80GB partitioned to Windows atm)

I appreciate any and all advice :)

Before 4.0 I would hands down of said yes, in the past i have 5 boxed on my Macbook Pro! However im a Imac user and have found that at points it has been v. laggy with 3 or 4 wow's running. Definately give it a try, it would be interesting to find out.
Good Luck
Murk.