That said, one of the curious things about this question is that it wasn't immediately clear to me what Paul meant by "Space Opera." As a narrative tradition, Space Opera has been identified as the "high adventure" genre, often coupled, in some ways, to Planetary Romance (Burroughs, for example), but with greater reach, greater inherent optimism, and an extraordinary love affair with the infamous "sensawunda" (also: colonialism, but you can read John Rieder's book for that). It's a
genre that reminds us at once of the great history of SF and all that is wrong with it. But Space Opera does have a newer face. Some call it New Space Opera -- a crummy term, to say the least, but effective enough. I see this new type of Space Opera as a more serious version than its predecessor, not in the sense that old form SO lacks seriousness, per se, but more in the sense that New Space Opera, insofar as it exists, seems to be constructed on a frame of complexity and rigor. You might also say that NSO has a serious tone that seems absent from SO, though I am not altogether convinced that this is necessarily true, particularly since some authors identified with NSO, such as Tobias S. Buckell, seem to draw heavily from old SO. In other words: NSO may or may not exist, though there is probably something going on in SO that is distinct from the older form. The community should probably discuss this trend at length (maybe it has).
I say all this as a way to attempt to explore Paul's question, which seems to hinge on a concern with definitions. Since SF based in the solar system (that is, SF in which humanity moves about the solar system instead of remaining stuck on Earth or going elsewhere) has usually remained the domain of hard SF (not exclusively -- Burroughs again), I suspect that SO which takes on the traditional narrative forms are unlikely to sustain a movement in solar system SF (these titles are getting ridiculous, I know). It's not that there can't be sensawunda and adventure in our solar system; quite the contrary. Rather, it seems to me that SO has a tendency to look to far off, practically unattainable futures in which interstellar travel is a given, aliens (or human factions) are plentiful, and the wonder of exploration to alien (not extraterrestrial, per say) worlds is practically a necessity to narrative. That's what the community has made SO into for so long, to greater and lesser degrees (for taste, of course). My gut tells me that SO which clutches to local concerns will invariably collapse back into hard SF, though I cannot as yet explain why in any intelligent manner.
That doesn't mean SO in the SS won't exist -- a stupid position to take. It means that such writing won't take over the traditional form. There's something else in store for SO. Something that NSO, existing or otherwise, must be leading to. But I have no idea what that will look like in the end. Do you?