I could have sworn that Intel’s Atom Z520 processor did NOT support Intel VT-x hardware virtualization assist. And, yet according to Intel’s Atom feature matrix it, like the Z530, does indeed support it:
The major difference between the Z520 and Z530 appears to be clock speed (1.33GHz vs. 1.6GHz).
Neither the Atom N270 nor the N280 used by most netbooks provides hardware virtualization assist.