As they headed home from Las Vegas last Friday, the roughly 2000 designers and developers — not to mention Microsoft employees — returning from the three-day MIX09 web conference in Las Vegas had plenty to consider.

For O'Reilly author and Silverlight MVP John Papa, the big news was the support for "out of browser" and line of business applications announced for Silverlight 3. For Vertigo developer Jon Galloway, the SketchFlow designer planned for Expression Blend 3 and demoed for the first time at MIX, promises to revolutionize the way designers prototype their user interactions. Brad Merrill of InfoSpaces and a former member of the Microsoft CLR team was surprised by what he saw as a new emphasis on good industrial design in conference sessions.

As for Scott Guthrie, VP of the Microsoft's Developer Division, reflecting on his keynote at an after hours reception, he was just pleased that MIX09 had come together without the "fire drill" of years past. And in his keynote he drew a big round of applause when he revealed that in spite of its "thousands of new APIs" and "hundreds of new features" the Silverlight 3 Beta download is 40K smaller than the one for Silverlight 2.0.

One of the notable departures of MIX09 from previous gatherings was a fresh emphasis on good industrial design, which could be seen even in keynote slides. On Day 1, Microsoft principal researcher and design expert Bill Buxton framed the talks that followed with his demonstrations of the rewards of giving customers the experience they crave in using a product. On Day 2, Designer Deborah Adler punctuated Buxton's remarks with the story of how adoption by Target of her radically different drug containers and labels was winning the Company new pharmacy customers. On Tuesday night, attendees were treated to a private screening of "Objectify" a new documentary on, you guessed it, industrial design and its role in the success of new products (citing, ahem, Apple, among others). And there was little code or markup to be seen in either keynote.

In contrast to the excitement and applause that accompanied demos of the latest Silverlight 3 and Blend 3 features, the final release of Internet Explorer 8 (IE8), while welcomed, seemed anti-climatic. Most of IE8's features have been known for months and its developers have blogged frequently and in great detail as MIX approached. Reaction remains mixed, with a good review from Preston Gralla of Computerworld and a not so great review from Walter Mossberg of the Wall Street Journal ($).

In three years, MIX has become Microsoft's showcase for RIA (rich internet application) technologies. Unlike Tech Ed, a conference for professionals looking to get more out of their existing tools and systems, or the Professional Developers Conference, where new stuff is announced, MIX is a gathering where web designers and developers can mingle with key Microsoft teams to discuss their work.

Silverlight 1.0 had its debut at MIX07, and Silverlight 2.0 was unveiled a year later at MIX08. This year, while the keynotes were not filled to capacity as in years past, and the attendee party at TAO was noticeably subdued, the Silverlight once again took center stage.

Of the more than 120 sessions offered, more than one third were devoted to Silverlight 3 Beta 1, the next version of Microsoft's RIA browser plug-in, while the next largest number featured demos of the just-released Preview for Expression Blend 3, Microsoft's tool for designing rich UI for both the web and desktop.

In addition to the "big three" of Silverlight, Blend and IE8, there were dozens of announcements, each important to a segment of the developer community and ranging from BizSpark, a program to assist early stage web startups, to new Eclipse tools for building Silverlight RIAs on a Mac and RIAServices, a new .NET library that simplifies the building of n-tier Silverlight line of business applications.

And what about mobile, many wondered? Silverlight for Mobile is in "private beta," said Guthrie during an informal Q&A at 3rd Place, the popular conference smoozing room. "We're working hard on getting to a public beta," he said, while suggesting that the carriers presented more obstacles than the software itself. One non-Microsoft insider who asked to remain unnamed, said in private that he had seen the beta and "it rocks."

Taken together, the several announcements and hundreds of new features promise to take the Silverlight web platform to a new level. But final release is still months away. Silverlight 3 will release "later this year [2009]", while an availability date for an Expression Blend 3.0 Beta was not given. The demo of the SketchFlow feature of Blend 3.0 was a runaway hit with everyone who saw it, but no bits are included in the Preview released for download at MIX.

Microsoft seemed to have two competitors in mind as it rolled out its new technologies. The first, clearly is Adobe with its Flex and AIR tools. "Don't forget the 'magic of three' [in our release version numbers]," said Blend General Manager Douglas Olson during his "Future of Expression Blend" talk. It was a clear reference to Flex 3 and a claim that Microsoft has reached parity with its rival. There was little talk of the second, however: aside from some demonstrations of compatibility with Chrome, Google was hardly acknowledged.

Read more from John Osborn.