Thats a great idea considering most software these days are coded without the needed use of register_globals and fopen not commonly used on alot of software. With updated software, phpsuexec/chmod, register_globals off, etc will help slow or even stop the script kiddies (lol
hackers) from causing harm.
Good idea to apply the changes on all the servers and for those that needs those to be enabled to just place an .ini file in those directories.