I'll wait for PS3/PS4 support before trying it.
In my opinion, easy access to the service on the TV is the most glaring barrier to entry right now. I have a Roku which is one of the bigger family of streaming devices (based on what I've read for the US) and neither CraveTV nor Shomi have channels(apps) for those right now.
Even for at least some of the devices that do stream to the TV, the CraveTV user interface is so bad that it's more problem than it's worth. For example, I recently became a subscriber to CraveTv via my Movie Central subscription on Bell Satellite TV and receive it through my 9241 receivers. In spite of my general criticisms of CraveTV content it does have a few things that I wouldn't mind watching. For example, I went to check out The Wire the other day and there appears to be 60 episodes. As far as I can tell there is no easy way to access where you left off, so to watch that series you have to remember the episode you are on and navigate through 60 episodes to watched the next one. The interface is so cumbersome and sluggish that I just can't be bothered right now. I'll wait until they improve on it. It's tolerable for movies and single episode shows.
Another barrier (at least for my wife and I) is regular TV (PVR'd) and Netflix. Between those two, we just don't have the time to get into another TV program. Maybe in the summer.