I don't feel MC17 was mature and stable enough to stop its development and force us to buy MC18 if we want more features and stability...
MC? Stable? You're kidding, right?
I don't know what their plan is but stability has never really seemed to be part of it. It's a heckuva tool, one I've paid for many times during upgrades. I find it's utility features unmatched in other tools. Thus why I purchase it. But I don't really make much use of it as an media playback tool. It just never rises to a level of polish or stability that makes me interested in trying to trust it to do that particular job. It's ended up being a lot less hassle to turn over audio zone playback to devices like Sonos. Lots more money, sure, but they're wife-friendly and reliable. MC does all the grunt work of managing the tracks and such, but it's just not a good fit otherwise.
I'd be optimistic and say "someday" but that day hasn't come in the YEARS of development. Too much creeping featuritis and not a lot of follow through on the hard parts of UI and real-world usability.