You may have noticed that it was a while since SQL 2012 SP1 was relaesed. Microsoft keeps pumping out Cumulative Updates which include many fixes, but these CUs include a disclaimer that you should only install them if you experience a particular problem corrected by the CU. Several of my MVP colleagues encourage people to install CUs, but I personally find it hard to recommend this to people on a general basis given the disclaimer.
I have submitted a Connect items asking Microsoft to SQL 2012 SP2.
I like to stress that you should only vote for these Connect items, if you really think that service packs are needed. If the CUs meet your needs, and you don't care about Service Packs, don't vote. Or vote down, if you think that releasing service packs (which requires quite some testing effort) is a waste of time, and Microsoft should focus on improving their cloud story or whatever.
Here is the URL:https://connect.microsoft.com/SQLServer/feedback/details/814656/release-service-pack-2-for-sql-server-2012
I'm posting a similar post in the SQL 2008 forum for service packs for SQL 2008.
Erland Sommarskog, SQL Server MVP, www.sommarskog.se