The minute you announce your wedding, the world around you starts to change. People understand that you are pre occupied with wedding planning (which is true) and keep non wedding related talks to a minimum.
Sometimes they keep secrets from you only because they are looking out for you and don't want you go be disturbed by matters that can wait till after the wedding. On the other hand a few might use your wedding as an excuse to keep you in the dark.
Either way remember this, once your wedding is over, you might just be out of the loop about the news in your circles.
Solution? Remind you family and friends that if it's something they need to talk about, you are there for them. There is some stuff you really shouldn't be bothered with as a bride, but for everything else, keep an open ear.