Yeah, I'm assuming my case would be complex enough also...I forgot to mention a Stakeholder pension in addition to the above. At least I don't own a property or have a mortgage, but I'm (optimistically) hoping that my salary may exceed $100k one day. I have no idea whether my aggregate total tax liability in the last 5y will exceed $25,000, but I would doubt it.
From my perspective it seems like a very expensive accounting exercise without benefit to myself or the US government. I think it's worth paying the renunciation fee however, provided that won't instantly catapult me into the immediate attention of the IRS...