The "new" navigation is not only default, it has been around since 2010. I don't even know why there is an option to stick with the old. But I am going to check into this.

Yeah I just did a google search and it was moved out of beta in July 2010. But like I said...I am going to check into this. It may be that they phase it out like they did with old profiles.

I wanted to let you know that they removed the option to switch! Locking as resolved.