Some would argue that the government will eventually have to start paying for all the "free" stuff it's been giving people for the last several years, and higher taxes would seem to be the most obvious way to do that. Today's rates, by comparison, are historically low. As such, it's entirely possible that you could have less taxable income in retirement and still be in a higher marginal tax bracket.This is correct. If you expect a lower tax rate in retirement a traditional mathematically makes more sense. If you stay at the same tax rate until death then it doesn't matter - the math ends up at the same spot.
There are some other advantages to a Roth - it's much nicer to your descendants with the new 10 year rule. This will lead me to converting traditional to Roth over a number of years. It should have some tax advantages (though they may not be huge), but if my kids do inherit it works better there.
This is true, but in both cases you get growth in a tax free environment. The math does work out to be equal if your tax rate stays constant.