By default, IIS 7.0 limits the maximum size of any request. Those of you who have implemented SharePoint 2007 on Windows 2008 are very familiar with this; specifically, modifications must be made to the web.config for your provisioned web applications setting maxAllowedContentLength to an appropriate value (the default is typically way too small). This is described fairly well in http://support.microsoft.com/kb/925083 (check the More Information section).
It's not obvious that this same limit will impact content deployment, but it does. Content deployment performs an HTTP upload of the exported content (packaged as CAB files) to the destination farm - even if the content deployment job is an inter-farm affair. As a result, if you ever find see messages in your event log complaining that the ContenDeploymentJobDefinition failed with an error of "The remote server returned an error: (404) Not Found.", you may just be running into this problem. Remember, you are uploading the exported content to the Central Administration (or an instance of Central Administration) on the remote farm. You'll need to increase the maxAllowedContentLength value for that web app, otherwise you'll get 404 errors (subcode 13).