Personally I think it'll come out in late 2016/early 2017 and will be the successor to the 3DS. These 4 things lead me to believe that:

1. The 3DS came out before the Wii U, traditionally this means the handheld line should be getting a refresh first.

2. Late 2016/early 2017 matches up with how often Nintendo is refreshing the 3DS line and assuming the New 3DS is the last 3DS (the name indicates it is), it would make sense for a new line to start instead of another 3DS.

3. Nintendo recently ordered free form screens from Sharp, they will be ready in 2016 (the year the NX might come out). Assuming these are not for QOL or that the next home console has a screen on it's controller (unlikely :( ), these will be for a handheld.

4. AMD will have a ARM chip ready for a gaming device in 2016, ARM chips have always been used in handhelds and the timing matches up with the screens and the NX.

These things could of course also match up with it being a "hybrid", but I don't believe such a thing exists.

Oh and BTW, the Fusion rumor had nothing to with a "hybrid" console. It depicted two consoles, a handheld and a home console. The specs also indicated they would both have separate games.