The book still has things to tell us, and I for one have experienced the problems in communication that increased team sizes bring. You should be aware that unit tests, separation of concerns etc. are not new concepts.
However, some things have not stood the test of time. I don't believe that writing ASCII flow charts in your code is a good idea, and the "surgical team" approach suggested has been tried by several people (Charles Simony at MS, most famously) and found not to work too well.
