It took me around 5 weeks to get approved back in 2007.
due to lot of scammers and cheaters,Adsense has changed its policy of Accepting new sites a lot.But it has not announced till now....
May be they just wanna keep it secret just like the pagerank algorithm..
Your safest and quickest bet is to sign up for a blog on blogger, post a couple of posts, then apply for adsense. You will be approved immediately.
That rule only to be sure about your site quality.
but if you can make a best quality site before that and if they think you are going on right way then they will approve you.