Like you, we will push back any RMD-induced creep up the tax brackets in later years by doing iTRA --> Roth conversions. But I won't go crazy over it:
-- Who knows what might happen to allow the government to tax Roth distributions (directly or indirectly--VAT, higher taxes on SS due to total income from all sources, etc).
-- By the time I reach RMDville, the remaining road is a bit shorter and if high taxes are a problem it means the nest egg has done well for us. In the home stretch and with the wind at our backs, paying taxes will hurt a bit less than it would today. Maybe.