I've never been a fan. I think it more likely that we have gravitation wrong. One possibility is that G has changed over time. Also, I've long wondered what effect instantaneous gravity would have on our model of the universe. Gravitational waves have yet to be directly detected. EDIT: This just in.
I'm not alone! Without any physic culture I hate the dark matter/energy idea. Supposing a new type of matter seems the worst complicate explanation one can come with. I'm more incline to believe in the MOND: Modified Newtonian Dynamics ( http://www.astro.umd.edu/~ssm/mond/index.html ) I mean it's more easy to believe gravity change when on very large scale than an invisible new matter explain everything.
Preach it. I've never understood why apparent inconsistencies between gravitation and observation should be such a strong foundation for an extremely exotic form of matter. I'm partial to gravity acting instantaneously, as if the entire universe is a quantum condensate. It's probably not the case, but it makes a lot more sense to me.