I'm a very long-time Adobe user, and this can only be good. Here are my guesses where the product lines merge:
Photoshop and Illustrator remain as the pro tools. ImageReady gains from technology in Fireworks.
GoLive and Dreamweaver merge into the best web design app out there.
Fireworks and Freehand go to the corporate/home market along with PageMaker.
LiveMotion gets dumped, Flash rules, but gets better SVG support.
RoboHelp gets integrated into the PDF workflow technology. Also look for some technology sharing between PDF and Flash.
Non-competing tools like InDesign, Director and Captivate stay alone.
In freaking out over product lines, don't forget that many of Adobe's and Macromedia's products were also formerly acquisitions. Adobe got PageMaker from Aldus, and Macromedia got Freehand. Adobe acquired GoLive from GoLive (taking the company name, and original product name, for the CyberStudio product). Macromedia acquired Allaire, getting ColdFusion. Dreamweaver's programming tools came from Macromedia's acquisition of Elemental Software, getting Drumbeat (then dropping Drumbeat and angering a lot of people). Macromedia bought RoboHelp and with it Captivate from eHelp.
So this is just another integration step, and hopefully with it better software. I think Adobe/Macromedia needs this in the Web area to compete with Microsoft Visual Studio.
I am a Freehand user since Aldus Freehand 1.0. I have used it heavily for line illustration, logo design, web layout design, poster and brochure design and everything else. I have always preferred it over Illustrator. I am curious to see what is in store for me with this change.
According to many tech writers I've talked to recently, RoboHelp is dead. Macromedia got rid of all the developers, and the product manager left. Macromedia didn't bother to show up at their booth at the recent WinWriter/WriterUA conference.
Many writers had already switched from RH to either Author-It or WebWorks Publisher, neither of which is an Adobe or Multimedia product.
(Some of the former RH/eHelp/BlueSky folks have formed a new company, www.madcapsoftware.com, to develop an XML-based authoring tool.)