Before starting developing this integration we made a (quick) investigation of the current integrations between Alfresco and SugarCRM. We found two projects on the SugarForge (and none on Alfresco Forge):
Of these the first one is still in planning stage (for how long?). The second one seems more to be a view of the Alfresco repository inside SugarCRM documents module than really using the Alfresco DM capabilities to integrate with Sugar.
Then I got a comment pointing out this integration between SugarCRM and KnowledgeTree. Though it is not Alfresco I think this is more what we are aiming for. Thanks for sharing this project, it could really be use full when building the SugarCRM extension!