The headline above is the takeaway I get from the "disclosures" by the Romney campaign that just went up an hour or so ago. All they're saying is percentage of adjusted income spent on taxes, not whether the income is virtually eliminated by tax strategies like write-offs from capital losses. If the vast majority of his $250 million is in investments that lost money, and he made some money on speaking fees that paid normal income taxes, his overall tax bill would be not that much larger than someone in the upper middle class.
What they need to do is show the tax returns, which would give some way to examine if they've been playing games. Failing that, they should at least provide brief details with actual amounts paid in each of the years they've summarized, just like they did for 2011. If we believe the summaries released today, Romney did pay taxes every year, but we don't yet know if the taxes amounted to a hill of beans.