Awesome
Burp-NessusLoader
Burp Suite extension to import detected web servers from a Nessus scan xml file (.nessus)
Intended Workflow
This extension will parse a .nessus file and extract any ports that were identified as web servers, including those encapsulated with TLS. Right now the Burp Suite API does not allow an extension to spider/crawl multiple targets in one task, so instead of spidering/crawling these targets and creating a ton of tasks, it just adds each of them to the current target site map. You can then start scans as required.
Building the extension
First thing you'll need to do is export the Burp Extender API Interface files somewhere and then copy them all into the src/burp/ directory. This is done from within Burp Suite itself on the Extender/APIs tab.
After that all you need is Apache Ant installed (it is likely called just 'ant' in your package manager) and running 'ant' will build the jar.