A test for the OpenSSL Heartbleed vulnerability was released just as this vulnerability was announced and is available as part of our complete set of tests.
If you have scanned your servers since update #259 came out, you are already scanning for this issue and can search for it by selecting Vulnerabilities > Details, and then searching for Test ID 16582.
To check if your scanner is updated, select Admin->LSS and in Signature column, make sure it displays signature level 259 or above.