Surface Pro runs with 64Bit tablet PC which is supported by Core i5 Ivy Bridge CPU, while Surface RT is a 32Bit tablet PC.

Surface Pro has the same security with Windows laptop. And it has built-in Bitlocker to protect data.

And it has a 10.6 inches screen with 1920*1080 resolution. Besides that Surface Pro is equipped with Mini Display port, Full-size USB 3.0 port, micro SDXC Card Port and so on. By the way, the stylus is also provided.
Editor from CNET said that tablet running with Windows 8 developer preview supported by i5 CPU is faster than iPad2. And if that’s true, Surface Pro which supports Windows 7 apps would be attractive especially for business people.