Wizards has been doing some good work recently bringing out-of-print D&D titles back, including issuing new print runs of the AD&D 1st edition rules, the 3.5 rules, and soon the 2nd edition rules and some modules (S1-4, A1-4).
The good news today is that they're re-releasing the pdfs of out-of-print books through RPGNow / Dungeons & Dragons Classics. That's a good thing. Even better, they're rescanning the books and giving folks access to the updated versions of pdfs they had purchased in the past (before the pdfs were pulled in April 2009).
That's great news as well. I bought the Known World Gazetteers through RPGNow a long time ago, and the scans of those were really badly done. I was still ok with the purchase -- I was living in Hong Kong at the time and didn't have access to print copies. But I'm looking forward to newer, better Gazetteer scans showing up in my RPGNow bookshelf one of these days.
Keeping these books available just makes sense. It was precisely because of D&D pdfs that I was able to play B/X D&D in a Hong Kong coffee shop with a friend (Ben Lehman) in Tsim Sha Tsui in 2006. That was around the time I had started fixating on that particular version of the game again, in the middle of a fun but sometimes slow-going 3.5 campaign. Keeping the game accessible electronically is what makes things like that possible. So kudos to WotC for getting this stuff back in digital print.