is multisite the right solution

I am wondering whether multisite provides the solution I am looking for.

Here is my dilemma.

I have a website which is fairly established (over 3 years old) and was built by developers before I got involved myself. Recently I discovered drupal which looks like it provides all of the answers to my prayers with regards to this site, however as the bulk of the site is already coded I was wondering whether multisite would be a good solution prior to a full site migration.