I've seen this come up several times in JIRA Forums and in email we've received: the need to connect JIRA with Salesforce.com. Last week I got an email from Rob at CustomWare that they had written a set of plugins for JIRA and for Salesforce.com to allow bi-directional integration. They are looking for Salesforce.com customers to assist with perfecting these plugins and help make them production ready. If you can help out or want more details and screenshots, go to this write up.