As we prepare our comprehensive reviews of new iPod models, we wanted to share some early discoveries with you, covering all four of the new 2009 iPod models. There are actually a lot more than 15 new details below, but we’ve grouped them into categories for easier reference. Enjoy! 15. iPod shuffle (Third-Generation, Fall 2009 Versions): The latest color-swapped versions of this year’s third-generation iPod shuffle are not considerably…