The Surface Pro finally has a release day, which will be February 9th through various retailers in the U.S. and Canada.
”Powered by an Intel Core i5 processor, Surface Windows 8 Pro provides the power and performance of a laptop in a tablet package and will run all Windows 8 applications as well as current Windows 7 desktop applications. Last month, we announced Surface Windows 8 Pro pricing starting at $899 and that it will be available in 64 GB and 128 GB models. A Surface Pen is included and makes for an amazing experience for writers, graphic designers or even engineers, and with Palm Block technology writing and drawing is fun for everyone on Surface Windows 8 Pro.”
Obviously the big difference between the Pro and RT is that the Pro will run your traditional desktop applications. I have the Surface RT, and have no need for those apps on a tablet, but others will definitely have a use and preference for this.
More info on the Technet blogs.
http://blogs.technet.com/b/microsoft_blog/archive/2013/01/22/growing-the-surface-family-surface-windows-8-pro-availability-confirmed.aspx