I've said it before: WotC needs to turn DDI into a repository of all that is D&D - both past and present. This way, all D&D players would have an incentive to subscribe, regardless of their edition preference. Since the addition of older edition stuff would be a one-time-only endeavor, WotC could focus on the current edition and still make money off of its older products from those who prefer them.
For starters, take the AD&D core rules 2.0 and integrate them with the DDI database. Since it's all in a reasonably portable electronic format, this project shouldn't take more than 2 employee/months (if that much).
That would be good and not just for the older gamers who don't want to switch to new rules. How many younger gamers develop an interest in the classic stuff at some point? The problem is the old stuff is only legally available on eBay and some of the asking prices get nuts. It's all about rarity driving up the price, I see some of the same stuff with videogames which is just as irritating.
I think WotC handles these things very conservatively because of TSR's bad bsiness practices. Too many product lines, the D&D/AD&D split and so on really carved up the audience. So WotC seems to do everything it can to provide just one product line. However, there's still splits because D&D fanbase has grown to be massively unpleasable.
I want to believe that making the previous edition .pdfs available again without overly restrictive DRM will be a good thing for WotC and players. But honestly, I don't know enough about business to know whether this is actually true or not, I want it to be true so I don't have to rely on something like eBay to pick up a classic gem I missed out on before. Having limited reprint runs of classic materials might be a good alternative
IF it can be done cost effectively. Or maybe comrehensive compiled classic rules, though the old Basic D&D rules could just reprint the old RC.
Having character builders for the older rules would be great for some of use, but there are problems there too. It diverts resources from developing stuff for 4e players, who are probably a bigger base of users. There's always the "no Mac support!" complaints. And WotC has had problems in the past with these things, particularly e-Tools and Gleemax.
I doubt either the OGL or printing new material for previous editions will ever happen. It's just not worth it for WotC. The OGL I think is something that isn't necessarily good for a company over the financial long-term; the fact that people can just download the SRD or go to a webpage that has it means less reason for even the core books to be bought. Printing new material for older edition risks splitting the fan base; 4e fans will be angry they're not printing material for them, and there's the risk that it won't appeal to older fans anyway. I'm thinking particularly of everything that's happened with the Greyhawk line, so many bridges had been incinerated there in the past that too many people didn't come back, and then there were those whose campagins had so greatly diverged to to point where the material was at best difficult for them to use.
If WotC spent any manpower/money on releasing new material for older editions that would be splitting the market . . . and it would be a bad business decision.
The whole problem with splitting the market is the market has already been split, and a lot of significant damage was done back in the TSR days. To their credit, WotC did try to repair a lot of that damage when Adkinson was running things, but it wasn't enough for some fans. The whole "you're playing wrong" approach to promoting 4e probably inflicted some damage as well, as well as some of the big changes in tone and/or rules and blowing up the Realms.
I know some of the flavor of the older material might not appeal to younger players or seem dorky to them. I don't think this is WotC's fault. I think it's a general pop cultural fault as a whole that emphasizes generation gaps. It's been going on for a while, with roots back into the 50s and 60s, and I'm not sure it's something that for society is healthy as a whole. Yeah, some aspects of generation gap happens naturally as parents don't realize their offspring aren't children any more but still treat them as such when the kids are feeling the need to be more independant. But to play things up to such an extent where whole generations get estranged from each other and can't relate to each other seems dangerous and/or wrong to me for some reason.
Besides you know your group didn't have to accept the spellplague as written. I know many campaigns that simply ignored it and are still using the Gray Box for it's Realmslore.
Easier said than done. Ask some long time Greyhawk players how easy it is to ignore the Greyhawk Wars. These sorts of things go a long way to fragmenting player bases.