Terminator Salvation: The Future Begins

I am really confused here.
Maybe you have heard more of this than I have--considering I just heard of it 6 minutes ago--but there is a Terminator 4 in the works.
And, um, the cast looks interesting: Christian Bale is John Conner. Schwarzenegger is not in it.
Rumor is that it will likely be PG-13, while this was a bad thing for Aliens v Predator, Batman Begins was PG-13 and was awesome.
I don't really know much about the director other than he goes by "McG"... Kinda lame name. [see edit below]
I gather this from the links at Wikipedia:

Christian Bale stars as John Connor, the man fated to lead the human resistance against Skynet and its army of Terminators. But the future Connor was raised to believe in is altered in part by the appearance of Marcus Wright (Sam Worthington), a stranger whose last memory is of being on death row. Connor must decide whether Marcus has been sent from the future, or rescued from the past. As Skynet prepares its final onslaught, Connor and Marcus both embark on an odyssey that takes them into the heart of Skynet's operations, where they uncover the terrible secret behind the possible annihilation of mankind.(link to original article)

There is an IMDB page too.

Making things more interesting is the fact that a teaser trailer will be shown at The Dark Night. I am eager to see it, but, after Terminator 3, have no expectations yet for this. I'm going to try to hold back on wild speculation until I see the teaser. But the rest of you are free to speculate as you wish. You may begin now.

[edit]
I just came across this which makes me feel a bit better about the director. It's the movie site/official blog or something. The part I like is that he admits his name is ridiculous. He also says that "the movie comes first and it will be protected at all times" about the PG-13/R rating.