Quote fromI must be insane for thinking this but I just hate it when people announce things.
ETA: One month? Why don't you just finish it and post it after you're done?
A variety of reasons.
A> I may want to poll the forumers and see if an idea would be popular
B> I might need to recruit help now and again
C> I need the encouragement of "This is gonna be awesome!" comments
D> Advertising and hype buildup.