Yes, that is correct. The full system requirements are:
Windows
* Windows Vista, Windows XP SP2, or Windows Server 2003
* 128 MB RAM (256 MB recommended)
* Dreamweaver CS4, Dreamweaver CS3
* Works with PHP 4.2 +
Macintosh
* Mac PowerPC or Mac Intel
* MacOS 10.4.x, MacOS 10.5.x
* Dreamweaver CS4, Dreamweaver CS3
* Works with PHP 4.2 +