A new report on Friday confirms earlier talk that on May 20th, Microsoft will be unveiling at least one tablet powered by a Intel processor. One source claims that this mystery tablet will feature a powerful Haswell variant of Intel's silicon, instead of the Atom version (like the Intel BayTrail). With that in mind, we would expect to see the Microsoft Surface Pro 3 see the light of day on the 20th, along with the Surface mini. Consider that the Microsoft Surface Pro 2 is powered by the Intel Core i5-4300U, which is a Haswell variant.
Outside of the rumored Intel CPU, no specs have leaked for the rumored Surface Pro 3. Besides being powered by the Intel Core i5-4300U, the current version offers a 10.6 inch screen with resolution of 1080 x 1920, 4GB of RAM and as much as 512GB of storage.