By having your script listed in both the Gallery and Script Center Repository you can ensure that there are more access points for your contribution to the community at large. Let's elaborate. Consider the following scenario:
The scenario above was added after recently reviewing the SharePoint related scripts on the TechNet Gallery and noticing that quite a number of these contributions were not listed in the TechNet Script Center. Here's hoping that script publishers in the SharePoint community moving forward will ensure that their scripts are available in both locations. Please keep in mind that this cross listing issue exists for many products.
When contributing a script to the TechNet Gallery and writing the script description, follow the procedure below to add a code example that will ensure that your script will be listed in both the TechNet Gallery and the TechNet Script Center Repository.