[Techtalk] Server Deployment

[James]

Question:

We're deploying our new inhouse web based application suite in the Fall.
The issue has come up in my head of how to deploy our servers.

Do we really need a separate MySQL server (ie, separate web and SQL)?
Right now, the development machine has Apache and MySQL on the same box.
Does it really increase performance (or only under high loads)?  What
are your thoughts of MySQL server replication?

If you have any anecdotes, they are most appreciated.

- James