Forum posting listing "a (hopefully) thorough list of all 4th Edition products published to date." Official Wizards of the Coast releases and special (not generic GSL) licences only.
Most items are links, it seems with precedence to official publishers page, but where that is lacking the the second most common link is to RPG Geek.
Regarding completeness: "There are a few sections of this Guide that may not be complete. The list of promotional items for 4ed is definitely missing some items; collectables for the latest edition are not as well documented as those for earlier editions. If you are aware of anything that needs to be added, please let me know. Also, the list of web releases and articles is somewhat selective. I've tried to list only those articles that were not also part of Dragon or Dungeon magazines for the month they were published, and which contained at least some 4th Edition game content. I didn't list any of the previews or excerpts, since those cover material which also appears in the books."
(user summary containing quotes from the post)