Information week had an interesting article that talks about the different methods of licensing used, ranging from the what we're used to with MS to the 'processor value unit' used by IBM to others even more...complicated. I think over time MS will have to change their licensing policy for SQL or increase the cost of the license to offset decreasing revenues as we're able to put more and more load on a server. None of the options discussed in the article really seem very palatable, at least to me - someone who likes the pay for it once and use it a long time model!
It's almost the perfect storm, CPU vendors driving up the number of chips per core, and at the same time virtualization is about to really take off. Licensing schemes for software are pretty bad already, I'm not sure this will make things worse as much as different. I suspect I'd opt for the simplicity of a subscription model over the more convoluted calculations that would probably result in me paying about the same amount of money anyway. It's worth paying attention to; any change could have a dramatic (probably negative) impact on our ability to deploy new SQL servers to to upgrade versions (because they are licensed per core and next version might not be).