> How it supports? Is each char of a string 2 bytes? Does it call now the
> wide WinAPI functions (CreateFileW instead of CreateFileA)?

Delphi 2009 has a new string data type: UnicodeString. It is UTF-16
encoded. The string data type is now UnicodeString. Previously it
was AnsiString. All Windows API has now refer to W version.

You may visit the following for more information:

http://dn.codegear.com/article/38437
http://dn.codegear.com/article/38498
http://dn.codegear.com/article/38693