Analytic firm IDC recently gave Microsoft's Surface line the credit for being the trailblazer in the detachable category, although Apple currently is the leader with the Apple iPad Pro. There is also talk that the second-gen Surface Book will see a nice boost in screen resolution from the current 2000 x 3000 to include a 4K resolution screen. And the USB Type-C port will allow for faster data transfer speeds, and perhaps the ability to use a smaller secondary display.
The Surface Book was first introduced about seven months ago, and while there haven't been any leaks to speak of, Microsoft could unveil the Surface Book 2 as early as next month. The good news for those who are priced out of the market right now, is that such a move by Microsoft would allow them to significantly cut prices on the original Surface Book.