Speaking with a McIntosh person recently about as to whether they would be replacing their 750 model music server. His answer was no. Explaining for companies like Mac, with wanting to get a product right the first time and at their standards takes a good amount of time. Time in which in that area of technology the next new thing is out so fast, it is not worth it for them.
My take on it is that with smart and clever choices, one can have a music server with their laptop as the base which sounds great and is very convenient and is very inexpensive.
It is just not worth it for companies whose products cost into the thousands to try to complete in that arena. They stick to the heart and soul of a system.