Tonight at 7 pm EST on CNN's Erin Burnett Outfront, there will be a feature on Romney's offshore accounts, including the tax planning motivations that one suspects may underlie them. I gather that Erin will name me as a source (via e-mail correspondence) for the basic tax analysis.
Nothing surprising or novel, at least so far as my contribution is concerned. Apart from the secrecy angle, which I assume isn't tax-related (as it's hard to believe Romney would commit outright fraud), I emphasized the tax planning objectives of avoiding (1) certain deduction limitations and (2) the debt-financed UBIT rules. David Miller discusses these issues, and others associated with using offshore entities, in much greater detail (though without specific reference to Romney) here.