I would take into account the Unicode string handling situation that appeared from D2007 to D2009. The changes associated with this step can greatly affect your application (only you can say that). In addition, you will need to consider what third-party tools / libraries / components you use. Not everything got to D2009, and probably some less popular components will never be able to jump at all.
D7 D2007 ( , ). , , , Delphi, .Net.
, - - , .Net, , Delphi. , , Delphi Win32.
D7 D2007/D2009, D7 .Net; , !