Two words on the new Pope: oy vey.
If I were a progressive Catholic, and I wanted to express my displeasure with Ratzinger, I'd call him Pope Ratzinger instead of Pope Benedict. His half-rodent, half-slapstick name is too good to pass up. But I don't know the rules around calling the Pope by his, uh, nom de Pope. Is it a sin to call him Pope Ratzinger, or just incredibly disrespectful? I don't want to encourage sin.
Suppose it is a sin to call him anything but his nom de Pope. Do you have to include the number in there too? "Pope Benedict the Sixteenth" is such a mouthful, whereas "Pope John Paul Two" had kind of a chunky rhythm to it. Will I be forgiven if I leave out the "sixteenth" bit? And if the number is morally mandatory, do I have to write it in Roman numerals? If I write "16", am I "letting [my]self be tossed and 'swept along by every wind of teaching'"? I would, after all, be adopting the heathen post-modern Arabic numeral orthographic system, instead of the numeral orthographic system of Christ's culture. Would I spend eternity in the Xth circle of hell? Am I being a moral relativist by asking these questions, or what?
Seriously, though: call him Ratzinger, if that suits you. Do it while people are still familiar with his nom de fallibility.