Since this is a binary package, it comes with a MySQL Client API version that will most likely not match the version of MySQL Server you are currently using, or would like to use in the future. Ideally, your client and server should match for best reliability, so only use this package if you don't know how to compile PHP yourself.
For example, the MySQL Client that comes with this package matches MySQL 4.1.14, so if you have MySQL 5.0.18 installed, then some functions may/will fail. It may not make much difference to the average user, but just know that it is best (and recommended by mysql.com) that your mysql client api is at least current with whatever server version you use.