If the only thing that you've heard about OAuth2 is that it is "insecure" then I'd like to say it is impossible to come up with the generic specification that will ensure the security of your application.
If you have invested some time into analyzing the specific OAuth2 flows and found the conditions under which the security can be breached then it is obvious that a care needs to be applied to whatever OAuth2 flow is deployed depending on how open the application, etc.
If you haven't subscribed yet to OAuth2 discussion lists then I'd like to encourage you to do it and follow up.
IMHO, OAuth2 will affect deeply the way we write secure web services in the years to come. A lot of innovation will be coming in in this space. OAuth2 will become much bigger than a classical 3-leg OAuth flow popularized so much by OAuth1. The complexity is already and will be there no doubt about it, but one should remember that OAuth2 can always be just a simpler and more effective evolution of OAuth1. It is difficult to beat the flexibility of it with respect to supporting all sort of grants, tokens and flows.
As far as the classical OAuth2 flow is concerned it is probably just a matter of time before the user authorizing 3rd party applications will have the optional legal effect and all communications with 3rd party intermediaries will move online. The browsers will probably support it the same way they support the certificates from the well known providers.
It is a natural fit for the current Big Thing: Cloud and Big Data. In fact OAuth2 is the next Big Thing.
Be positive about OAuth2 and get up to speed with it now :-). A healthy ecosystem of open source OAuth2 implementations is growing.