I think serving ads crosses a line. If you were to bring this feature, I would hope that you would offer an ad-free version for those of us willing to pay for it. The key is, I block all ad servers, and if that disables the program I will move on. IMO, you should be thinking about a "pro" version, price point ~$75, that incorporates the audiophile features being requested on the forum. You'll get plenty of gripes, but everyone will buy it.
Streaming has great mass appeal, but I think it should be a FREE, ad supported, low-end version, with high-end features disabled. Essentially music match, which, IMO, isn't worth a second look, although plenty of people love it.
On the topic of ad servers, I would like to see space allocated on the forum server for the avatars people seem to love so much, so that third-party hosts are no longer involved. We can still have the scary falcon and the ominous HAL lens, we just have to store it somewhere secure.