Should I mention a professor's name in my SOP for MSc if the professor is only taking PhDs? Some facts:


I am applying for a Master's program in Computer Science at a university in US. 
My research interests exactly match with the professor's. 
I am applying to the university because of the professor. 
The professor is only taking PhD/PostDoc students in his group. 
He has just joined after completing his PostDoc and there is no information on the website if he will take any courses.
Chances of directly doing a PhD with him are very less based on my profile.


The problem:

I understand that whether or not I should write his name or mention some of his work depends on if he will be able to advise me during the program which is exactly what I do not know. 


Can having discussions with him during his office hours be a good enough primary reason to study there?
What could be the possible reasons that a professor is not taking any Master's student? Is there a good chance that if I get an admit, my regular interaction with him, interest, and work will make him take me in his group with PhDs?
There is no reason you shouldn't mention the professor's name and your interest in his field. It will show that you are focused. 

In the US, the master's degree is often (usually?) seen as a step along the way to a doctorate, so you will probably be perceived that way in any application. Also, a Master's in the US will usually not be entirely research focused and will include quite a lot of course work. You will be able to meet with him if you are accepted and can work toward some relationship with him. If you think you aren't quite prepared to work under him as a PhD student, the work toward the Master's degree should get you closer to that goal. You might also find that your goals change, of course. 

Since he is a new professor he isn't likely to be tenured. This can be a problem for students as he will be very focused on his own research and work towards tenure. This means that he may have less time for students. He may also have an agreement with the university that he can focus for now on his research with (only) advanced students. 

But treat work with him and his group as a tentative thing. But stating that you have an interest in that can do you no harm and may serve you well.