Sonny
Adventurer
I agree that while hitting the 40th anniversary would be nice and they shouldn't take more time than they need to (for a variety of reasons), I think that the impact of the 40th Anniversary may be getting a bit overestimated in this thread. D&D is not going to suddenly be dominating the news cycles just because it's a semi-major anniversary, and while WotC could and probably will incorporate it into the marketing in some fashion if it lines up, I don't know that "40th Anniversary! New D&D!" is a significantly stronger marketing pitch than "New D&D!", or one that will reach way more people. It's not that I don't believe that there's not some person out there who's going to read the four-line sidebar in Time magazine's minor news items column and then decide to play again, but I'm not sure that that guy is necessarily a ton of guys.
I do think that later release dates are a lot worse for a lot of reasons, most significantly that while D&D still has about eight trillion times as much general brand recognition as the rest of the industry combined, its stranglehold on the mindspace of people already within the hobby has been gradually loosening for a while, and not having an active product certainly doesn't staunch that.
I don't think anyone is claiming the 40th Anniversary will dominate the news or bring in a ton of new people. But it will give D&D more visibility and mind share then it's had in years. Especially when table-top RPGs currently have near zero visibility with the general public in recent years. It will help D&D Next.