Executive orders are intended to be a means for the executive to perform his duty to faithfully execute the law. They give direction to lower levels of government about how to implement congressionally enacted laws, they are not meant to be laws themselves, at least in principle. Some of Obama's EOs many be purely administrative, or contain necessary practical administrative instructions. Others may be discretionary, or may exceed the president's lawful authority. It is the latter class that can be summarily countermanded.
For instance, the president could order the armed services to perform instruction in “race relations” on an annual, monthly or a weekly basis, or not offer any instruction or guidance. Either option is within the scope of his power and responsibility. A new president could change such a policy with his phone and a pen.
I believe some of these that he signs actually continue EOs that have been in place by past _residents.
Obama's shiite stain on America is going to take some time to get rid of but Trump is starting on day one and that is good.
I just hope he has a rubber stamp instead of a pen. His fingers are going to be tired eliminating this muslim skidmark from our history.