It's great to see this previously Playstation console exclusive coming to other platforms. I can see more and more PS popular franchises coming to the Switch.
Agreed, and i think we're going to see the same from many 3DS franchises. The Switch is going to force a lot of SD franchises to jump into HD development, which is going to make porting many of them to the PS4 an attractive proposition (especially Japanese titles looking to broaden their international reach). Likewise though, the Switch being a popular HD system makes it a lot more viable for titles that have previously have skipped the 3DS because of technical limitations.
All in all i expect both Nintendo and PlayStation gamers will be pretty happy. They're going to 'lose' exclusives, but they're going to gain access to more games. Seems like a good trade to me.