I think you'll need to define "traditional" independently from any particular previous game system before we can really answer this.
That aside, I think you'll find one major flaw in your premise - avoiding the "edition-expansion-new edition-expansion" cycle. This cycle is part of the basic economics of selling to a niche market, which quickly gets saturated. The cycle is the only clear way to keep the market from saturating with your product - by changing the product.
I would have said "Fantasy Heartbreaker" myself. The very premise of it — something very, very, very like a game you're already playing, but juuust different enough that you could theoretically love this one all the more, and could there be enough people that all feel the exact same way that it would be the Number One Not-D&D Game? — is the philosophy that has already launched a thousand such rough beasts.
You need lightening in a jar...
No D&D clone will ever take off like D&D has, since D&D has carved that road AND has name recognition to boot. You're best bet is to completely avoid the Tolkienisms (elves, pointy-hats, orcs, etc) and try something new (or, since there is nothing new under the sun, a different combination of existing components that hasn't been done).
What that is though, is the lightening. Steampunk? Modern? Savage World? Horror? Swashbuckling? Pirates? Asian? Wuxia? All these have been done.
How much market share did Exalted grab when it came out?
As hobbiests, I suppose we want to know how many people are playing each game and how often, but if we're discussing market share, we're interested in revenue -- how many dollars of Exalted products were sold.The thing with RPG market share is that it is hard to ascertain in that it overlaps as gamers tend to play different games at different times. So you can't really say that "60% of gamers play D&D, while 25% play Wod, 10% Exalted, and 5% everything else" because some of those D&D player are also playing Wod AND Ars Magica AND Buffy AND...etc.
But my sense is that Exalted, for a very short time, was the 2nd most popular RPG out there, then it fell back down below Vampire and/or WoD as a whole. I could be completely wrong, though.
As hobbiests, I suppose we want to know how many people are playing each game and how often, but if we're discussing market share, we're interested in revenue -- how many dollars of Exalted products were sold.
Well, Steve Jackson mentions 2007 gross sales "close to $2.88 million" -- of which Munchkin represented more than 70 percent. The bulk of the rest went to GURPS, but that's still well under $1 million for their entire RPG line.Right, and I wish the figures on RPG economics were available. I would love to see how much $$$ Talislanta has sold vs, say, Ars Magica. I remember Ryan Dancey putting together something, at least in terms of gamer demographics, back at the start of 3E, but haven't seen anything since.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.