How standard is the standard library?

[steve.leach]

Newbie question: Looking through my stack of books and various on-line 
references, I have seen several libraries and library functions listed 
as depreciated.

Is there a road map or concrete list of what parts of the standard 
library are to be considered reliable and permanent?  Coming from C, I 
am used to library functions being set in stone.

Can I reasonably expect that code using, for instance xml.dom.minidom 
will still work in 10 years?

Do all depreciated libraries print warnings when they are imported?  I 
see that if I print xmllib, I get the message "The xmllib module is 
obsolete.  Use xml.sax instead."  Is this behavior followed 
consistently, to give a "this code might not work come this time next 
year" warning?