2008 Trek Madone Geometry; same as original 5500?

I havef the old school 5500 from back in the day (2000) and am in dire need of an upgrade. With all the new generations out there, I have gotten a little lost…I am looking at the new madone coming out, and know it is a sloped frame, but I was curious to know, if I was 58cm in the original 5500, whether I would go for a 58cm in the new frame.

I am going to try these out of course, thinking either the 56cm or 58cm, but was just curious if you guys knew the answer…Thanks.

And if you could cite how you know (work for trek, best friends with president of the company etc) it would be greatly appreciated.
Hve an awesome weekend!

-Steve