We're talking about CS4 here: Flash was basically THE way to build UI back then. I wouldn't be surprised if it was one of the motivating factors for Adobe buying out Macromedia (aside from just quashing potential competition from Macromedia Studio).

Hell, a lot of high-budget video games around the same time used a little thing called Autodesk Scaleform. That's basically Autodesk's reimplementation of Flash Player (Adobe was too short-sighted to pursue this market) which game developers could quite easily license and embed into their games.