*Update* This is now fixed in VirtualBox 4.0.7 and above: https://tickett.wordpress.com/2011/05/17/virtualbox-issue-in-osx-on-new-macbook-pro-i7-2011-update/
Finally having got round to migrating my virtual machines over from my old MacBook Pro to find they’re running like a dog!
I messed around for ages- even tried creating a new VM but no joy!
A bit of googling turned out a bug which has only today been flagged as critical: http://www.virtualbox.org/ticket/8474
Let’s hope it’s fixed ASAP!