DunDraCon 35 just concluded yesterday and among its many seminars was one hosted by Chaosium, in which its president, Charlie Krank, announced that there'd be a seventh edition of Call of Cthulhu released in time for GenCon this August.
Listen carefully -- you hear that sound? That's the sound of Call of Cthulhu players across the world not rising up in anger or exultation that Chaosium has decided to release a new version of the venerable Lovecraftian horror. Why is that? Are Call of Cthulhu just more mature than D&D players? Are they less resistant to change? Are they just not as invested in their favorite game as D&D fans are? The answer to all of those questions, in my experience, is the same: no.
The reason CoC fans aren't incensed by this news is that each new "edition" of Call of Cthulhu is backward compatible with the previous one. With a few exceptions (such as the shift from 1st to 2nd edition, where Charisma became Appearance and Magic Points replaced Power Points), the biggest changes between editions are in terms of art, layout, and content. A new edition might include some new sample adventures or expand the list of Mythos entities or spells, in addition to incorporating errata and fixing typos. Otherwise, though, Call of Cthulhu hasn't really changed that much and it's perfectly possible to run a scenario published in 2002 with your characters generated according to rules published in 1983 without the need for any conversion. How many RPGs can say that?
Long ago in the pages of Dragon, Gary Gygax mused about the possibility of D&D eventually reaching the state where it could be considered "perfected," updated only periodically with new art, layout, and errata to keep it "fresh." That day has never come nor is it ever likely to do so. Perhaps because, unlike Call of Cthulhu (or indeed any other RPG), Dungeons & Dragons is a big business, the backward-compatible, incremental change model Chaosium has adopted just doesn't make business sense. I can't really speak to that, because I've never produced anything that made me millions of dollars -- alas! And given that Chaosium has, more than once, been on the brink of financial collapse, I'm not sure that its business practices can be held up as a model for anyone, let alone the caretakers of the only RPG ever to get its own Saturday morning cartoon.
I can only say that, as a player, I adore the way Chaosium has handled new editions of Call of Cthulhu. It's probably why I own so many of them, even though there was no necessity that I do so in order to "remain current." Maybe that's no way to run a "real" business, but I like it nonetheless, which is Chaosium continues to get my dollars and other companies do not.