The pot legalization laws in Colorado and Washington did draw objections from the DOJ. However, as it stands now, the federal government will "look the other way". This tolerance policy will end if the fedgov perceives abuses (e.g. sales near schools). And they are watching closely. This situation is a lot different from "Federal Law Nullification".
The Fedgov may look at schools and age requirements, but other than that, I don't think they give a damn. Our Fedgov is now run by hippies.
You really believe that? Colorado has passed a law that essentially nullifies Fedgov law in their State. Have you heard of Holder's DOJ actually suing them as yet?
When he does, I will agree with you. Until then, Colorado has gone against Fedgov law and so far has not experienced any penalties. And yes, I happy about Colorado saying up yours to Fedgov even if it means some 18 year olds can get high on pot. So what? They do it every day with alcohol.