Speaking as someone who has actually worked on a hypervisor on VT-x on a 1st-gen MB, I call totally unforeseeable bullshit on you. Sucks to be you! ;)

In fact, every Intel Mac runs at least Intel Core, and VT-x very slightly predates Core (you can get P4 parts that have it). It is in fact slightly easier to run a hypervisor on the original Core, and thus the first-gen Macbook, because the Core 2 Duo runs userland in 64 bit mode and the kernel in emulated 32 bit mode, and that's a gross oversimplification made as a small mercy.

In any case, every Macbook sold today --- even the cheapest one --- runs at least Core 2 Duo, which includes not only VT-x but also the advanced I/O stuff Intel did to make TLB flushes not kill performance.

Long story short: you can't buy a Macbook that doesn't do just fine with Parallels or VMWare Fusion.