Jason Calacanis, a major figure in the blogging world, has decided to leave AOL, the first major aftershock of Time Warner\u2019s surprising decision this week to replace AOL\u2019s Chief Executive Officer (CEO) Jonathan Miller with a television industry veteran.Calacanis made the announcement early Friday local time on his blog, a little\u00a0more than\u00a0a year after joining AOL. Wooed by Miller, who became his mentor, Calacanis sold his very successful Weblogs company to AOL in October of last year and continued to run it as a standalone subsidiary.It became clear that Calacanis\u2019 profile was rising under Miller\u2019s supervision when Calacanis was given free rein to reinvent the venerable Netscape Web portal. Calacanis relaunched Netscape in June as a social news site modeled after Digg.com, which lets readers submit, comment on and rank stories, but with a heavier editorial and journalistic oversight.Shortly after Time Warner shocked the industry on Wednesday with its announcement that it had replaced Miller, Calacanis wrote in his blog that "today was very sad for me" and praised Miller for leading AOL\u2019s bold business transformation, calling him "a quiet samurai of a leader." Calacanis was referring to Miller\u2019s mission to reinvent the once-dominant company by focusing on online advertising and distancing it from its roots as a subscription-driven provider of dial-up access that reserved most of its content and services to paying members.Miller, who joined AOL as its chairman and CEO in August 2002, had received praise recently from industry analysts and observers, because the AOL transformation from a "walled garden" proprietary service into a freely accessible Web portal has been yielding better-than-expected financial results, with strong growth in advertising revenue.In addition, Miller had been credited with pushing AOL toward embracing new Internet technologies and services through in-house development, acquisitions and partnerships, a key ingredient for attracting a critical mass of visitors to its websites. At an appearance last week at the Web 2.0 Summit in San Francisco, Miller reiterated his belief that it\u2019s critical for AOL to invest and focus on products and technology.In the past, AOL had erred too much on the side of making its products and services integrated with each other and easy to use, sacrificing quality along the way. "The emphasis today is to make stuff great," he said at the conference.With Miller as its CEO, AOL became a player\u2014with varying degrees of success\u2014in emerging, popular areas like online video, digital music, social networking, social news and blogging, and revamped its more mature services like Web mail and Internet search.It was in this context that Calacanis joined AOL, and his sudden departure raises questions about how much internal damage and distraction Miller\u2019s sudden ouster will have, particularly at a time when AOL\u2019s top managers must be intensely focused on executing the new business strategy.Miller\u2019s replacement is Randy Falco, who was previously president and chief operating officer of the NBC Universal Television Group.Neither Time Warner nor Calacanis immediately responded to requests seeking comment about his resignation.\u00a0 -Juan Carlos Perez, IDG News Service (Miami Bureau)Related Link:\n\nNBC Executive to Be New AOL CEOCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.