Maybe Bungie is not Valve, originally Half-Live 2 was supposed to be followed by quickly released episodes (I.E. DLC) instead the episodes took forever to come and they were rather meaty, and well, there were only two... now we are left with tons of questions until the next game comes to be
This is just to point out that these ideas are not entirely new and it's not a given that it will turn out as Bungie envisionned it.
As for the reviews delays, I think the only think you could not figure out by yourself until very close to release was how long the story mode was (around 8 - 12 hours) which is not nearly enough for me to give a damn about it... not until I find it half price!... with all the complaining about the review events game journalists get, people should be happy (at least I hope those complaining about review events or review copies being handled to the gaming press in advance are not the same crying wolf because reviews were "held" to hide comething hideous). Anyway, yes, the beta was well received, I wonder why the cold shoulder on metacritics!