Not sure if this is the right place to ask this question, but I really cannot find any information on the Web. Boost 1.48.0 has been out on the website for two days but there has still been no update on yum. I just want to make sure if everything is right.
There is already a bug/feature request to upgrade to 1.48.0 for Fedora 17. There was a similar one to upgrade to Boost 1.47.0 for Fedora 16 that mentions Boost 1.48.0 wouldn't be released in time for Fedora 16. It looks like you'll have to wait for Fedora 17 to get Boost 1.48.0.
A page on the wiki also has more info on Boost 1.48.0 for Fedora 17.