They don't update their blog anymore, however they do still update in these following links:
Forums: http://forums.blackmesasource.com/
Black Mesa Wiki: http://wiki.blackmesasource.com/index.php/Main_Page
Black Mesa Twitter: http://twitter.com/BlackMesaDevs
And the screenshots you probably seen are from the Media Section on the website or the Black Mesa Mod DB page, they are outdated screenshots and do not represent what the mod currently looks like, they upload more recent screenshots on the Black Mesa Wiki.