Well, the Galaxy Gear, according to many was a flop in terms of sales, and yet it was the biggest-selling smartwatch of the year, enough to warrant a sequel (even if the rumors point to it being Tizen-powered and not Android-powered).
As for the Zoom... I just couldn't see myself getting the S4 one, and the idea still remains for the S5 if it comes out. It's just too bulky for it to be a phone. If it was bulky all throughout the body, like an 'old' phone, then I'd be OK, but this thing is thin on the sides and huge on the middle... I can't imagine using that comfortably. But like you say, this is a niche item after all.