Stargate Atlantis Season 4-Doppelganger & The Seer

Its looking like Season Four is going to be very different from what we are used to, which is a good thing. I think its going in a very dark direction which is good I guess as long as their is still the comedy in it, I don't mind this. Doppelganger was nicknamed NOAS( Nightmare on Atlantis Street). I think this episode will be very interesting because its Sheppards Doppelganger that is doing some bad things in everybody's dreams ( It will be interesting to see what everybody dreams about as well). 

Another episode that I think everybody can't wait for is The Seer, where a Seer comes to Atlantis to pass on all his knowledge and he also knows that Teyla is pregnant. Now, this was totally shocking for me and totally out of the blue that someone on the team is going to be a parent. What was even more shocking was that they were planning on making McKay a dad but didn't want two main character's being parents at the same time. It will be interesting how this will all play out. 

So my question, how long do we have to wait too see season 4? because it sounds very good.