I don't know if this should be updated to the Wiki yet, but AOS is coming to the Burlington Mall. I was there last weekend and they still have the construction barrier up but it sounds like its coming very soon.
I happened to be at the Burlington mall this weekend and saw that. If you sign up for their "brotherhood" they will give you a free starter set when the store opens. (TheArtofShaving.com/grandopening). I usually go to Colonial Drugs in Harvard Square. But, driving/parking can be a pain in the winter, when compared to the incredible ease of biking in during the warmer months. I take 95 on my commute drive right past the mall, but am always looking for a smaller shop where you can get to know the owners/employees and they can get to know you.