This isn't really a surprise. In the popular media, the more flamboyant SpaceX and their manned Dragon V2 capsule have been getting the attention, while behind the scenes Boeing's CST-100 was widely picked as the favorite. It looks like NASA wants to be everyone's friend, because they picked both.
Really, NASA played it a little safe and picked Boeing more than SpaceX, giving Boeing $4.2 billion for the development of their orbital ferry, well over the $2.6 billion granted to SpaceX to develop the manned variant of their already-flying Dragon capsule. NASA's always been about redundancy, so having parallel projects for something as crucial as access to orbit shouldn't be too shocking.
Both ships are, roughly, Apollo-derived concepts: mostly conical re-entry capsules with cylindrical service modules aft. Boeing's CST-100 is a little closer to the Apollo's form, but a bit larger, while the Dragon has a more elongated profile. According to NASA's specifications, both capsules will need to carry between 2 and 6 astronauts, and both will use a dual-tiered seating approach that originally was developed as a special Rescue variant of the Apollo command module:
Both capsules are capable of landing on ground. The Dragon V2 uses a retro-rocket based approach to cushion the landing impact, while Boeing relies on large air bags, possibly as a result of their partnership with Bigelow Aerospace who has extensive experience with inflatables, thanks to their R&D into inflatable crew habitats.
Boeing's experience with NASA and producing hardware for the space program for decades is the most likely explanation for their choice as the primary recipient of NASA's money. Still, the amount given to SpaceX is hardly trivial, and it looks like the US will have a choice of ships to ferry our people to and from the ISS, leaving NASA free to focus beyond Earth orbit.