Hey,
I have also applied to the Masters program with preference of 'Materials and Structures'..So this has got me worried now, what do you mean by the lab is not doing well (just curious to know)?
By the way, congrats on getting in MIT Mech department!!
I have still not received any email and Beth said that they will be sending out emails as the admissions committee is still compiling the results...
What is more scary is that I am an international applicant (so even lesser chances)...still hopeful though!!