Agamon
Adventurer
"Very little" seems completely impossible to argue. More effort than any other edition and than most RPGs, was the reality:
http://www.wizards.com/dnd/Article.aspx?x=dnd/updatesarchive
Remember this page? No other TT RPG or edition of D&D has been remotely as thorough, that I'm aware of (would have been even better with a free-to-access SRD though, if 4E had had that). We got constant updates, which happened BEFORE THEY APPEARED IN THE DDI (!!!!!!!!!!) too, and got discussion from the creators about why they happened which didn't require DDI access.
Huh. This is Exhibit A for when I show people how not to design an RPG. Video games are often released unfinished and patched later. Annoying, but acceptable, as the patch becomes invisible once applied. Dozens of pages of errata are not invisible and become nearly unusable the larger the volume of errata that appears.
Nobody's perfect and all games need fixing of typos or even a bit of tweeking to rules, but 4e was pretty obnoxious with its abundance of errata.
Happily, it seems WotC learned from this, and we should be back to nominal errata for the new edition.