There's a meeting now underway in London on Outstanding Questions for the Standard Cosmological Model, which is the term for the current Big Bang/ Inflation/ Dark Matter/ Dark Energy/ Accelerating Universe view of the history of the universe. Tommaso Dorigo is attending, and reports on the talks on his blog (and also a description of lively debate).
Some people would probably deride this whole meeting as a waste of time-- I know where I'd look if I were interested in finding an example-- but I think it's great that somebody's doing it. The ideas listed on the slide pictured in one of those posts sound pretty far-fetched, but it's important that somebody does the work to check them out. That's how science works, after all-- its important to poke at all the weak points in our theories, even if they seem unlikely to fail. This is particularly true for a theory as recent as the Cosmological "Standard Model," which is extremely recent, and has a lot of vague points still.