I have no time to create my own settings and adventures, so I like buying them and adapting them to my own needs (although I hate system conversions). Now I'm a bit worried: if I switch to 4E and WotC becomes my main supplier of books, I think I will notice a quality decrease.
A current downside to 4e is that there is not a lot of setting or adventures designed for the system if you do not want to convert stuff.
For settings I think statless is fine (Scarred lands gazeteer, Pirate's Guide to Freeport, etc.). You want to know god cosmology, kingdom details and politics, group identities (racial, religious, guild, etc.), and some history. Statblocks for NPCs are not essential for this. Converting settings from one system to another is not that tough IMO.
Adventures are a sticking point if you don't want to make up your own or convert old ones but use ones designed for the system you are using.
There are H1, H2, and a few dungeon adventures from WotC. There are a few 3pp ones (adamant entertainment has a 4e rat man one out already that is not under the GSL). Goodman will come out with some soon. Presumably some new companies will enter the market as well.
It will take time for WotC to create more. It will take time for the 3pp publishers willing to make 4e ones to come out with them.
Whether this is enough for your needs depends on how much you game, how quickly you go through modules, and how much the modules offered are to your tastes.
Look back on your 3e experience, think how it would have been to just have WotC modules, Dungeon (under nonpaizo control), Goodman Games, and a few other 3pp publications but no Paizo OGL, Necro, Malhavok, or Green Ronin Adventures.
I don't know where other prolific 3e module writers stand on 4e (AEG [not sure it is still in business], FFG, Monkeygod [no longer doing RPGs], Atlas Games [no longer doing D&D] Troll Lords [doing just C&C?]).