I have been able to display comments since day one, but its been via SQL and crystal reports off a replicated database :)
I bet you could use raw SQL code in the report designer to get the data out of the reportprocesscomment table, but it will be in HTML format so nearly unreadable. We came up with a couple of functions to make it ( sort of ) readable for when we migrated all our ServiceDesk tickets back into helpdesk 6.
We also have functions that calculate business hours for us we created in v6 and kept using them in 7 instead of trying to figure out how to do multiple business hours ( based on customer )