If you're using the regular Workfront user interface, you can setup prompts for users to filter the report at run-time.
It would be extremely useful if you could also allow reports to be filtered by including api-style parameters in the report URL. The report would still display as a regular report within the Workfront UI but the user would not need to select the prompts.
This would open up a lot of possiblities when linking to Workfront reports from other systems (e.g. filter down by customer ID etc).
Taking it a step further it would be really nice if you could specify the fields and groupings to be used. Basically giving you the same flexibility of an API query but with the output rendered as a report within the Workfront UI.
Users would of course need to be logged into Workfront for this to work...that's fine.