Nowadays, both Facebook and mobile broadband become popular. I think that the future of Blogger may not be bright.
In Facebook, one could share and have interactions with friends more easily. If I need to share photo with friends, Facebook is a better choice than Blogger. "Note" in the Facebook could be used as dairy like Blogger. People may not want to log-in to different websites to share nor reading friends sharing.
Another threat to Blogger is mobile broadband. As people could write share their feeling using mobile phone like Iphone or Android and using mobile phone to input data is not so convenient, they prefer writing something short just like Twitter. They seems not to use computer again to share in Blogger.
Last but not least, it seems too difficult to be distinguish among the blog website. Wordpress, Xanga and Yahoo! Blog are also popular. Any company could set up a similar blog hosting like Blogger. A little more functions seems not so important. Moreover, Blogger aims at English environment and lack of localization. For those whose mother language are not Engish, they may not prefer Blogger.