Google has been on a shutting down spree starting with health, powermeter, labs & now Google directory. Directories were once the top source for link juice & over time directories have lost value. DMOZ is still the king of the directoires & google also drew a lot from DMOZ for its directory. It is no longer available & visitors to the site are suggested to use Google search for information.
Directories provide link juice to the sites which would help site get better page ranks & rankings in Google. Many directoires charge for premium listing. However, with the growth of social media, PPC & others, directories is losing their sheen. I beleive, Google's closure is the final nail on the coffin for the directories. With this Google is stressing on unique & fresh content, which would be used in Google ranking & in accordance with Google Panda update.
Google's panda update, instant search, using social media results & real time search have added a new dimension to the search optimization. This shows Google is placing more focus on unique, fresh content which provides users with the good content & information. With this, reciprocal linking & directory listing have joined a bygone era.