They promised to support and update the system until September or October of this year, but it will never going to happen. No one is still developing apps for WP 7.8 (even Microsoft abandoned this system, look at Skype or Bing Weather/News/Sports etc that are not supported by WP 7) and is officially dead.
Also, at the end of 2014 could be released the new WP 9 so no reason to keep working on the 7. I have a Lumia 800 and very disappointed of this... but this is the way is going to be.