My new Thinkpad W520 has been a great investment for multiple virtual machine software development purposes. Configured with an INTEL CORE I7-2920XM processor, solid state primary drive and 16GB of memory the multiple virtual machines run about twice as fast as my older Thinkpad T41p.
I still use my Seagate 500GB hybrid drive as my secondary drive, where I have all of my virtual machines located; the primary hard drive being used for the HOST OS only.
I am still using VMWare for virtualization, as was the case for the older Thinkpad T41p. No need to consider a move away from VMWare Workstation 7. I have been quite pleased with VMWare, after switching from the Microsoft Virtual PC product in 2009. I also use VMWare ESXi Server for the hosting environment offered to my clients.
The primary reasons I purchased the W520 include the faster processor, as well as the solid state primary drive and of course the availability of USB3. The faster processor plus USB 3 has reduced my full backup time from nine (9) to two (2) hours.