Hachamovitch noted that Microsoft's research showed that 62% of the top 97,000 websites world-wide fall back to HTML5 video in the absence of Flash, again mirroring Jobs' 2010 anti-Adobe comments.
Plug-ins, including Flash, will be supported by the desktop version of IE10, and users can easily switch between the two, to, for example, render a specific site in the desktop browser after looking at it in Metro.
Users can also set either version as the default for all browsing on a Windows 8 PC.
Touch-enabled devices such as tablets will presumably default to the Metro style IE10, and hardware powered by ARM or other "system-on-a-chip" (SoC) processors -- which will run only Metro apps in the SoC edition of Windows 8 -- will obviously offer only Metro IE10.
Hachamovitch also launched a pre-emptive strike against critics of the dual-IE10 decision.
"Pessimists may criticize what they will call 'two browsers,'" said Hachamovitch. "There's only one browsing engine, which you can use with two different 'skins [and] over time, the Metro style experience will serve more and more mainstream browsing scenarios."
Al Hilwa, an analyst with IDC, agreed that two IE browsers shouldn't trouble Windows 8 users.
"I don't see a problem with that, since the key underlying technologies are unified," Hilwa said in an email interview. "The two user-facing parts of the browser show how a developer can target both styles of using Windows 8 if they choose. Clearly, touch is a new way that requires a new model of programming and special attention, so this is warranted."
The Metro IE10 app is available only as part of the Windows 8 developer preview. That early look at the OS can be downloaded by anyone from Microsoft's website.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@computerworld.com.
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