Seems like the latest patches for KVM (the linux Kernel Virtual Machine module) has Improved KVM Performance.

"The happy theme of today's kvm is the significant performance improvements, brought to you by a growing team of developers. I've clocked kbuild at within 25% of native. This release also introduces support for 32-bit Windows Vista."

No all I need is a VT compatible CPU in my linux box to play with this stuff!