No, but clearly people are wanting Microsoft to take the bait.. This is being backed by the Desktop as a Service providers who want to be able to deploy this.

Unlike trademarks to my knowledge there is nothing that devalues their offering by NOT suing, and instead suing other providers, at least until it gets large enough. Hell they even make money on each windows 7 license they need.

On the other hand, I really don't expect Microsoft to do this. It might take them years to bother to sue, but I see them taking it on simply because they can't turn a blind eye to piracy.