Yeah you can do this I have it setup on my servicedesk to display tickets in a particular HD6 queue.
If you just want to access the data then, so long as the databases are on the same instance, you can use this SQL in the SD report builder to display the fields that you mentioned:
USE Altiris_Incidents /* Replace this with your HD6 database name if different */
SELECT T1.[Number] AS 'Ticket Number', T1.[Title], T1.[Comment], T2.[Name] AS 'Modified By'
FROM Workitem T1
JOIN Worker T2 ON T1.[Modified_By_Worker_ID] = T2.[ID]
WHERE T1.[is_last] = 1 /* This will show the last comment, remove this to show all comments */
AND T1.[status_lookup_id] <> '400' /* Excludes Resolved tickets */
AND T1.[status_lookup_id] <> '600' /* Excludes Closed tickets */
ORDER BY T1.[Number] ASC
This is just a sample. You might want to tweak the WHERE part, especially excluding (or including) tickets of a particular status or worker queues etc.
If however you want to directly edit the HD6 tickets through the ServiceDesk then I don't think this is possible unless you actually present the HD through the ServiceDesk in an iframe webpart or something similar.