One of the star attractions of Microsoft's Mix '06 confab in Las Vegas next week may not make an actual appearance.

For a few months, Microsoft officials have been telling testers to expect a first Community Technology Preview (CTP) code release of Expression Web Designer to debut during Microsoft Mix, which kicks off on March 20. That event is the Redmond software maker's first conference aimed as much at professional designers as Microsoft's traditional audience of developers.

But testers now say they are hearing they will not be getting a first CTP of EWD, code-named "Quartz," next week after all. And Microsoft officials are declining to comment on when the company plans to deliver the first build of Web Designer.

Nonetheless, Microsoft has slated several sessions at Mix '06 that will show off the expected tool and highlight how early private testers have been using the code. And a number of testers are anticipating Web Designer's promised capabilities.

"I have not seen Expression Web Designer to date, but the potential for tight integration to the other Expression tools means that it certainly holds promise for XHTML, CSS [Cascading Stylesheets], and ASP {Active Server Pages] interface design," said Nathan Moody, director of creative services at Fluid Inc.

There are a number of possible reasons that could explain the Expression Web Designer hold up, said Jacques Surveyer, a consultant and author of www.thePhotoFinishes.com and www.theopensourcery.com Web sites.

Surveyer said Microsoft might need the final code for Atlas, its AJAX Web client framework, which is currently in beta test. Or perhaps Web Designer is a victim of "the usual internecine warfare that occurs over Web and database stuff at 1 Microsoft Way," Surveyer said.

Another theory, according to Surveyer: "Microsoft has always regarded the Web interface as Public Enemy No. 1. Can you imagine the strategic battles that are going on over how much Web 2.0 thrust/Live should be allowed to do. This harkens back to the Java wrestling match of eight years ago."

EWD is one of three initial members of Microsoft's Expression family of tools for graphic designers. Other already-announced members of what could grow into a larger suite of products are Expression Interactive Designer (EID), code-named "Sparkle," and Expression Graphic Designer (EGD), code-named "Acrylic."

Microsoft has said to expect all three of these tools, which will be tightly integrated with one another, as well as with Microsoft's Visual Studio development tool suite, to ship some time after Windows Vista, which is currently expected to launch in November. Microsoft told developers last year to expect Web Designer and Graphic Designer, at least, to hit in calendar 2006.

Interactive Designer is a tool for creating user interfaces for desktop applications. Graphic Designer is Microsoft's first entry in the professional illustration, painting and graphic design arena. And Web Designer is Microsoft's next-gen Web-site design tool.

"Microsoft is competing with years of inertia built up by Macromedia and Adobe. We're currently an Adobe shop when it comes to design, but a hard-core Microsoft shop for development. We love that these worlds are coming together under the guise of XAML (Extensible Application Markup Language) and WPF (Windows Presentation Foundation)," said Scott Stanfield, CEO of Vertigo Software, a Microsoft services partner.

"We're sending developers and designers from Vertigo to Las Vegas next week," Stanfield added. "We may change our path once we see the new tools. We weren't too impressed with the tools the last time we looked in an early beta. (We) love the vision; waiting for the tools."

Microsoft has made test builds of Interactive Designer and Graphic Designer available to testers for several months. In January, Microsoft released CTP test builds of both products. And last week, Microsoft delivered March CTPs of both interactive Designer and Graphic Designer to testers.

The March CTP of Interactive Designer includes a number of tweaks designed to improve compatibility between Interactive Designer and the February CTP of WinFX, Microsoft's next-generation set of Windows programming interfaces and related technologies. The March Interactive Designer CTP also includes new grouping, drag and drop, data visualization and clipboard interactivity, according to Microsoft officials.

The March CTP of Graphic Designer includes enhanced compatibility between Interactive Designer and Graphic Designer, as well as between the February CTP of WinFX and Graphic Designer. It also includes new XAML export capabilities.

Fluid's Moody was upbeat about early builds of Graphic Designer and Interactive Designer.

He said Graphic Designer is "quite agnostic about the difference between pixel graphics and vector graphics. It's a very creatively enabling tool that, as it gets rolled into the Expression line and gets more XAML savvy, it gets more interesting with every update."

Interactive Designer's "layout management and XAML interface tooling capabilities are quite robust, and its ability to integrate 3D and video into the user experience is certainly compelling," Moody added. "The ease with which interface controls can be richly styled will guarantee broad appeal for many designers and developers. It's going to represent a very broad palette of options for creating rich interfaces."