Joel as a informative article about some of the pros and cons of email enabled lists in MOSS 2007.  While opening up user management of DL lists will work for smaller companies, larger customers will want to create Exchange Address book views in Exchange Systems Manager to filter those lists from the main root view of the Outlook GAL.  Administrators can then create a custom sub folder view (similar to the default "All contacts") for the Sharepoint list to be chosen via the outlook GUI.

Here is a snip about what to be cautious about:

Email enabled lists create contact objects in AD, it takes careful coordination to create these contact objects and ensure the proper write access to a specific OU.  Imagine 500,000 lists all with the ability to be email enabled.  There are also some huge wildly popular DLs.  That's a lot of freedom.  If you're not ready to manage it, I agree with the mentality of start small, understand the implications.  You don't need to turn on all the nobs, and start with everything enabled, but for some scenarios this feature alone is really the *killer* feature.  When you create a site it doesn't automatically create these objects, so you don't have to worry about that, in fact most will never even know it's there.  It would take some training to learn how best to take advantage of these features, but they are cool and very powerful.  When you delete a site, it does clean up these objects, but what happens when a site is deleted without the API or when a database is simply removed down the road.  That's right, unless the API is called properly you could end up with some contact orphans.  Naming standards for these objects?  No control really unless you build something.  So there are some considerations to be aware of.

Joel Oleson's SharePoint Land : Email Enabled Lists and Inbound Email