SharePoint 2010 has many wonderful improvements over previous versions. One of which is a vastly improved Content Deployment mechanism and API.
If your application makes use of Event Receivers or Feature Receivers, these can, depending upon what they do, cause problems during a Content Deployment job. If you have code that you’d rather not execute when your event is triggered as a side effect of a Content Deployment job, you can use the SPImportContext object to find out if a job is running, and if so, to take alternative action.