Embarcadero Technologies released the white paper on Unicode Migration written by Cary Jensen, with stories contributed by the community at large.
You can find it in the Embarcadeto Technical Papers page, which is different from the Developer Network technical papers page, and it is different from the RAD Studio in Action site hosting (for example) my paper. (I really think that a single master page linking all Delphi related white papers would be a good idea...).
Cary's paper is titled "Delphi Unicode Migration for Mere Mortals: Stories and Advice from the Front Lines" and is a superb paper. It is a recommended reading for anyone considering migrating his or her Delphi code to a recent version of Delphi, including Uniocde support.
I did write at length about Unicode in my Delphi 2009 Handbook, which probably remains a very good companion to this paper, providing more foundation material. But Cary's conversion scenarios are much richer and detailed, and he #34es extensively on the community experience (and also quite a lot from my book, with my full belssing). Coming much later, he also can see things I could not get in perspective (and are partially wrong in the book, as conversion experience when I wrote was very limited).
Again, a recommended reading to all Delphi develoeprs, those who already migrated (to see if they made it right), those in the process, and those still on Delphi 7 as they fear to migrate. Kudos to Cary for it, and to Embarcadero for asking him and getting the Delphi community involved in the process.