There is a happy medium between a bloated game system and what we have now. People need to stop being so extreme. Just because the OP is asking for more product doesn't mean they want hundreds of books. There is nothing wrong with wanting updated setting material. There is nothing wrong with wanting more adventures. I'm so happy for all of you that don't need any of that.
I think the issue is that WotC just doesn't have the resources to provide the products that a handful of us want. The reason why they aren't announcing anything is because they don't want to announce something and then have to say "sorry we have to cancel it". We've already seen this with Dungeonscape. We've seen it with the Adventurer's Handbook as well (and this wasn't even officially announced). They are focusing on what makes them money and it's not the RPG. It's a sad thing. It's not HASBRO overlording on WotC either. WotC is it's own entity and any losses on the RPG side are easily compensated for the massive CCG market that it has. Don't expect anything from them and maybe we will be surprised when they finally come up with something awesome.
Until then I guess we have to use material from editions that were better supported.
But that's just it. This release schedule *is* a happy medium at the moment. Five big books in the first six months? That's ambitious. Note that right here you're criticizing Wizards for "cancelling" a product that was never officially announced. ( And the stuff from that cancelled book *is* being released. FOR FREE. How can that possibly count against them?) I am positive that they have more releases that are being worked on right now, this very minute. They just want to not announce them until they can give firm, unmovable release dates. And, seeing them take fire for "canceling" unannounced products, I can certainly see why they've chosen to take this path.
TL;DR: Five books have come out in six months. That's a pretty fast release schedule.