I don't know anything about Adobe's or Macromedia's plans for bringing software to Linux, but for some of the software you mention, there are comparable alternatives that run natively in Linux. GIMP
, though not quite ready to take on Photoshop in preprint processing, is more than adequate for most users' needs. Scribus could probably be compared to PageMaker or InDesign (though I'm not very familiar with any of them). Flash may be a ways off, though I've heard it runs well in Wine. The Draw package that comes with OpenOffice
is excellent, and very well integrated with the rest of the OOo suite.
are supposed to be fairly nice web design suites, and there's a variety of different content management systems for Linux that can probably do better than Dreamweaver does for that sort of thing.
For real desktop publishing (pre-print, typesetting and whatnot), I believe Linux already has the upper hand, with TeX, LaTeX, Ghostscript, LilyPond
and so on (though they are also available for Windows).