In a post called "Skyrim — what we’re working on" over at Bethesda's official blog, the company admits that it has to take better care before releasing updates to its games. The post refers to the patch for Skyrim that was released earlier this week which caused dragons to fly backwards and make things like magic resistance stop working for some players. Bethesda acknowledges that the update adding bugs instead of fixing them is not a good thing ...
Here is the latter part of that post:
"We all know this is a huge game, and everyone has a different experience. We’ll continue to do everything we can to make the game better and better for as many people as possible every day. We’ve also realized that with the millions upon millions of people playing Skyrim, we need to treat our updates with greater care. If we get too aggressive trying to fix a minor issue, we run a risk of breaking something larger in a game like this. To be safe, we are prioritizing code side fixes right now over data fixes. Quest and balance issues are usually data, and those will start rolling in a large way with the January updates."
Bethesda said that a small update to fix the new problems will be released early next week - probably first on the PC version of the game because they have direct control over it and don't have to wait for either Microsoft or Sony to approve its release.
Source: Bethesda Blog