The handbags-at-dawn spat between Adobe and Microsoft over the competition between their Flash and Silverlight interactive Web technologies has entered a new round. Major League Baseball's decision to stream the 2009 season via Flash instead of Microsoft's competing Silverlight technology has drawn a backlash from a Microsoft group product manager who lists several major events that were or will be shown only on Silverlight.

Steve Sklepowich namechecked these US-based Silverlight customer wins: including last year's 2008 Olympics in Beijing, next year's 2010 Winter Olympics in Vancouver for NBC, CBS's March Madness on Demand college basketball championship games, and next week's Masters Golf Tournament for AT&T broadband customers.

In the UK, the technology's most high-profile customers are ITV and Sky for their online programming through their ITV Player and Sky Player Web applications. The BBC's iPlayer and Channel 4's 4oD services use Flash.

Outside of the sports arena, Silverlight also delivered President Obama's inauguration in January.

Skelpowich also countered Major League Baseball's claim that comparative adoption rates drove the decision to move MLB.com from Siliverlight to Flash. "While Flash 9 may have high penetration," he wrote, "the Swarmcast NexDef plug-in that helps power MLB's HD experience has virtually no adoption."

Still, even Microsoft only claims a 25 percent adoption rate for Silverlight among consumers worldwide. Compared to Adobe's claim of 99 percent, Microsoft has a long way to go. Sports and special events won't drive everyone on Earth to install and use Silverlight. Microsoft needs to win over sites with a much broader online appeal. I wonder what it would cost to get YouTube to switch?