Hard drives in consoles have been blessings and burdens. You no longer have to worry about losing your memory card or entering a code, but transporting your entire console just to head over to a friend's house is never fun. Let's not forget the the subject of hard drive failure; a matter of "when," not "if."
Starting March 10, 2011, PSN Plus members will have access to 150MB (1,000 files maximum) of storage space for game saves. Your files will be available from other systems, although they can only be recovered once per day in order to prevent piracy.