Clarification about master slave configuration in mysql

Question

We are planning to migrate an existing MySQL database to a new server using the MySQL replication master slave procedure.

Unfortunately this will take a lot of time so we were thinking of doing a dump of the MySQL central db, restoring the dump on the new mysql db, and then setting up the master slave procedure.

Will using the master/slave procedure after restoring the dump of the original database overwrite the data on the new server, thereby wasting our time with the dump/restore process? Or will the master/slave procedure replicate the data that was added to the old server after the dump took place?

I am using MySQL 5.1 on Debian squeeze.