This is indeed great news. Microsoft and Overstock as Bitcoin accepting merchants provide a big dgree of legitimacy.
Yes, very good point.
I think that average people will have much more confidence to use bitcoin if they see that such ''big'' and reputable company, like Microsoft, accepting bitcoin.
I hope that this is now final ''breakthrough'' and that many more ''big'' companies will follow Microsoft lead and also accept bitcoin.
This will help us to become mainstream, value of bitcoin will raise again...