Here’s a thought: there’s no such thing as the new space opera. — Jonathan Strahan
Of all sf’s subgenres, “space opera” seems to attract the most definitional fervour. Everyone seems to have an intuitive sense of what the term means, and no two people seem to have the same intuitive sense — as demonstrated in the comment thread on Jonathan’s post, where Ellen Datlow says
I find the current use of the term “space opera” exceedingly annoying and confusing.
To me “space opera” was and always will be simple adventures in space.
Space opera used to be a pejorative locution designating not a subgenre or mode at all, but the worst form of formulaic hackwork: really bad SF.
Many readers and writers and nearly all media fans who entered sf after 1975 have never understood the origin of space opera as a pejorative and some may be surprised to learn of it. Thus the term space opera reentered the serious discourse on contemporary SF in the 1980s with a completely altered meaning: henceforth, space opera meant, and still generally means, colorful, dramatic, large scale science fiction adventure, competently and sometimes beautifully written, usually focussed on a sympathetic, heroic central character, and plot action [this bit is what separates it from other literary postmodernisms] and usually set in the relatively distant future and in space or on other worlds, characteristically optimistic in tone.
Not everyone accepts this historical account (notably Brian Stableford in his NYRSF review of The Space Opera Renaissance), but the idea of a “new space opera”, which probably started either with Iain M. Banks’ Consider Phlebas (1987) or with Colin Greenland’s Take Back Plenty (1991) (and with M. John Harrison’s The Centauri Device  as an ancestral text), has gained enough currency for there to have been an issue of Locus that focused on the topic a couple of years ago. But among other things, this version of NSO seems to get conflated with the so-called “British Boom”.
In a second post, Jonathan asks for other peoples’ definitions of space opera. My own previous attempt at wrangling with some space operas, from a couple of years ago, can be found here, but it sort of sidesteps the question of definition. I like the definition that Jonathan quotes in the comments — “lovesongs to the way the future was” — since an awful lot of modern space opera does seem to have that sense that we can’t get there from here. But he also lists “[Alastair] Reynolds, [Iain M.] Banks and [Stephen] Baxter” as definite space-opera writers, and while I think the first two are probably fair associations (granting that both have also written non space-opera work), I’m not so sure about the third.
In fact, Exultant is the only Stephen Baxter novel I’d really call space opera. The majority of his output is something else. An awful lot of his books certainly take place in space — Timelike Infinity or Titan, for instance — or have a vast cosmological scope — The Time Ships, Time, Space. But he’s also written a lot of less expansive books, from Voyage and Coalescent to this year’s Emperor.
I think you could make a case for Ring as a space opera, but I don’t think I’d be convinced by it myself, and thinking about why leads me in the direction of a definition of space opera I’m more comfortable with. Ring deals with a group of last humans touring the far-future ruins of the galaxy. It probably qualifies, just about, as “epic space adventure”, although that implies a rather more upbeat tone than I remember the novel having.
But I wouldn’t call it space opera because of how the setting is handled. One of the thumbnail definitions of hard sf that’s sometimes used is that in a hard sf story, the universe is a character. Ring fits this definition: the nominal “bad guys” in the story are the enigmatic and extraordinarily powerful Xeelee, but they never come on-screen, and there’s every indication that they pay as much attention to humans as humans pay to ants. In fact, what the characters in Ring are struggling against is the cold infinity of the universe. You could say that there is a space opera story going on — the Xeelee have their own enemies, the photino birds — but we’re not a part of it.
Exultant, though set in the same sequence, is much more a space opera, to my mind. For starters, it has space battles. Lots of space battles. Space battles that have been going on for thousands of years on fronts hundreds of light-years across. There’s lots of gosh-wow physics, and some nods to how big and unfeeling the universe is, but the universe isn’t a character in Exultant: it’s a stage set. At heart Exultant is a human drama, in exactly the way that Ring isn’t. So space opera, we could say, cuts the universe down to size.
None of which, of course, tackles Jonathan’s original suggestion, that there’s no such thing as the new space opera. I’m not sure I buy that; at the very least I think that the post-Banks or post-Greenland British space opera is new, if only because, Harrison, Dan Dare, and Journey Into Space aside, I have real trouble thinking of British space opera written before about 1980. Suggestions are, of course, welcomed.