I think you are right. It will come later in the year. Maybe October.
The reason I am thinking this is:
-> Skylake is not out yet, and expected to come at the end of the year. Broadwell is not exciting. Might as well end up being a Surface Pro 3.5, where it will have nothing over SP3 beside the CPU and better camera with auto focus.
-> They released Surface 3, without doing an event (beside a small press event). The Surface 3 is targeted heavily at students. This is done as "just in time" before school start season. They would have not done this, if the SP4 was around the corner. If it was, both would be announced together. The Pro 4 is a flag ship system, so it makes sense to make a big press event for it. Why make a big event for a system that is slow, can really charge when turned on, and nothing really special, beside price, somewhat.
-> Microsoft needs to fix the throttling problem of the Surface Pro 3.. so a more power efficient CPU (Skylake) is a must.
-> Windows 10 development needs to be completed to know which feature to implement to really stand showcase Windows 10 with the Pro 4. For example, they can implement a keyboard cover that when you flip it on the back, it auto0switch to tablet mode.
-> Link to the last point above, the device needs to be 100% Windows 10 ready. That means that not only hardware needs to have official, solid, reliable, and optimized Windows 10 drivers, but also that it will get continuous support, and not "Yea here are Windows 10 drivers, and next month the hardware is dump, because: here look a new model!" type of situation.
-> Need to see what other manufcatures have in stores for Windows 10 system to make a device that stands apart.
The reason I am thinking this is:
-> Skylake is not out yet, and expected to come at the end of the year. Broadwell is not exciting. Might as well end up being a Surface Pro 3.5, where it will have nothing over SP3 beside the CPU and better camera with auto focus.
-> They released Surface 3, without doing an event (beside a small press event). The Surface 3 is targeted heavily at students. This is done as "just in time" before school start season. They would have not done this, if the SP4 was around the corner. If it was, both would be announced together. The Pro 4 is a flag ship system, so it makes sense to make a big press event for it. Why make a big event for a system that is slow, can really charge when turned on, and nothing really special, beside price, somewhat.
-> Microsoft needs to fix the throttling problem of the Surface Pro 3.. so a more power efficient CPU (Skylake) is a must.
-> Windows 10 development needs to be completed to know which feature to implement to really stand showcase Windows 10 with the Pro 4. For example, they can implement a keyboard cover that when you flip it on the back, it auto0switch to tablet mode.
-> Link to the last point above, the device needs to be 100% Windows 10 ready. That means that not only hardware needs to have official, solid, reliable, and optimized Windows 10 drivers, but also that it will get continuous support, and not "Yea here are Windows 10 drivers, and next month the hardware is dump, because: here look a new model!" type of situation.
-> Need to see what other manufcatures have in stores for Windows 10 system to make a device that stands apart.