I don't think corporations will ever fully embrace and encourage blogging. Why? Because blogging is about doing something for fun. It's about being open and honest. It's about debate. Most companies don't want their employees to have fun or be open and honest, and they sure as hell don't want to encourage any public debate about anything they are doing.
My guess is that if businesses do end up embracing blogging, they will ruin it. If you've ever been a high level executive, you have probably had some PR training. They show you how to plan your points and get them across no matter what a reporter or interviewer asks. Corporate blogging may turn into the same thing. God forbid we really say what we think.