I'm not convinced that this is really important. This site has a whole lot of long-time gamers. And sure, they'd love to see continuity. But, I'm not sure they are a large enough segment of the market for this strategy to be crucial.
I don't think I expressed myself clearly. I'm not necessarily talking about accessing the long-term gamers. For starters, I know that to-hit tables, Saves vs Death Ray, and descending AC, elements of D&D quite dear to my heart, are gone, gone, gone, never to return. For good or ill, WotC made a break with history in 2000, and there's no going back. The best that old-timers can hope for is something akin to Next, where the game can be turned into one that roughly emulates the TSR editions. Nor am I talking about keeping the game static. OD&D is different from AD&D which is different from B/X D&D which is again different from BECMI/RC D&D, and then 2nd Edition is different still. There's room for change, for improvement, both mechanically and presentation wise.
So I think there needs to be TSR-like continuity (distinct from continuity to TSR-editions at this stage!). While all the above are different, in some fundamental ways, nonetheless any adventure from one can be used with another, and a player of one particular of those editions could easily drop into a game of a different one. The reason is not because those old players are necessarily a revenue resource. I highly doubt TSR was getting a whole lotta of money from OD&D players in 1999. It's to maintain a steadily continuing fan base, with new players coming as old players leave.
As an example, I was brought into the game in 1987, by a friend using Moldvay Basic and Keep on the Borderlands. He eventually gave me his Basic and Expert sets because he was focusing on AD&D. When 2nd Edition came out a few years later, I don't believe he made the switch. But I bought the 2nd Ed. core books, because while I didn't have a strong connection to the 1st edition books, the 2nd edition game was essentially familiar enough that my characters and settings easily ported over. Even as TSR moved their focus from adventure modules and DM splats to campaign settings and player splats, they retained me as a relatively new customer because the material they made was largely compatible with my own.
WotC has not followed this paradigm, and as a result, the fan base has fractured much sooner and much more granular that usual. Even leaving aside how much of jump it was from 2nd Ed. to 3rd Ed., the 3.5 revision was not just an errata update, but necessitated a revision of much of the whole line. 4e rendered many of 3.x books mechanically useless. And the Essentials line was not so cleanly integrated into the market, as much as I like it. Someone who got into the game in 2006 or 2007, making their world and characters, found they had to start from zero again in 2008. And as much as I like Next, someone just getting into 4e is going to find most of their books and all of their characters pretty much invalidated* sometime next year.
This is what I mean by compatibility and continuity. To-date, every WotC edition has offered players a choice. Move your campaign over entirely to the new shiny, or just enjoy your old books. And not just old players, where this might be somewhat expected, but relatively new players as well. A player who started in 1977 still shared a common D&D language with a player who started in 1997. That in itself may not necessarily be a positive in a business sense (though IMO it is). However, a player who started in 1999 is playing a virtually different game from a player who started in 2004, who is playing a virtually different game from someone who started in 2009. On the whole, I think that's a negative, as a business strategy.
*Of course any fan of any edition can continue playing their favored edition, and I've long expressed the belief that one thing WotC wants to do with Next is create adventures and material that can be used with multiple editions, 4e included. Nevertheless, it won't be possible for someone to bring their 4e character into a Next game without heavy revision. I don't believe it will be possible to play a game with a Next DMG and 4e MM.