I'm considering doing this for us:
1. We've maxed our 2014 Roth IRAs already - to put it bluntly, I don't think we'll wind up with low enough MAGI to go 100% traditional this year, or next unless our income drops next year.
2. Once I've got that tax return more or less finalized in February or so, I may find that our MAGI is somewhere in the phase-out range. Maybe I will luck out and we'll be below the bottom of the cutoff, but probably not.
3. Based on 2, I may recharactize whatever Roth contributions we can to Traditional.
I'm also considering 'topping off' my solo-401K once the final numbers are in, but that's not as big a deal - should be within a few hundred on that one regardless. But every little bit of taxes saved now helps us get to the end goal faster.
Key point - you can recharacterize your contributions up to your tax filing deadline in the IRAs, so no need to worry about predicting your income 100% accurately in advance.