Deprecation is a term for "no longer the preferred way to do things."
If you receive deprecation warnings, it means you're using a method or class that is no longer supported and may be removed in the future.
If you receive these warnings, you should change you code to use the newer, preferred way to do things. You are not, however, required to change your code.
It's just a warning folks! Deprecated methods may be removed in the future, so don't sweat it immediately -- just get them changed eventually...