I think they are bad...

You know that feeling when you see game getting 90 and 100 and you are all hyped...just to notice its 1 month away.

But I only see this on PS3...Is it part of their strategy?

Well certainly Naughty Dog have finished the game with a month to spare, and they seem to be nicer on the embargos... I guess that is it, and I am sure that they do have some deal with IGN, who always seem to get early reviews, but I am not suggesting that it is simply the score that matters, more likely some advertising thing, and frankly, everyone has been talking about Uncharted 2 recently, so it is obviously working....

I what you want is for people to be talking about your games for as long as possible, and if early reviews achieves that, then it also allows me to play a little bit ahead of the normal review window of a week before release

Well if you look at Killzone2, Infamous, and now Uncharted 2 none of them were trying to fit into a specified time schedule, so the games were finished early. I personally enjoy the hype building up like how they're doing it, it makes it more exciting when you finally get the game and pop it in. You wouldn't in your right mind let them review a game one month early if you were afraid the game might not get a high score as a publisher, so it also shows confidence in the quality of the game.