Facebook is already being used as a dating service by many - including unsolicited messages from people regardless of your relationship status. (The only way I can avoid it is to not use a real picture of myself in the profiel.)
Considering that Facebook has had some problems managing personal data, I think this is an unwise move at this time. Zuckerberg needs to work on rebuilding the trust that has been lost this year first... THEN he can talk about adding a real dating service to the platform.
It feels like he is scrambling to regain ground lost this year - but in a "get rich quick" fashion rather than working harder to fix what was broken.