Yes, I think the new video-sharing app Ocho will fail. The idea of providing a new service to increase the length of videos by 2 seconds does not seem enough to make Ocho successful. If they had increased from 6 seconds to 30 seconds they would stand a chance, but not for an increase of 6 seconds to 8 seconds.
I think as long as Ocho launches an app for Andriod and other platforms in addition to Iphone it will not fail. People seem to love video apps and don't have a problem using more than one. I do think the market is starting to get tight for these apps and there won't be room for many more though.
Ocho provides users with another option for getting their little videos out into the world. With Vine allowing 6 second videos and Instagram allowing 15 second videos, Ocho provides a nice home for all those 8 second videos that people are just dying to post. What really looks fun about this, is the fact that even the comments section is video. That could lead to some pretty fun stuff
Yes, the video-sharing Ocho app will be successful as long as it differentiates from the existing competition in the space. There is room in the video-sharing social niche as long Ocho has a creative edge or novel solution not already implemented by sites such as YouTube. Otherwise, it is a possibility that Ocho could become a buyout target which would also constitute a success.