You can now create a salesforce.com task for prospects completing a form, accessing a file, etc. just as you would with any other completion action. Pardot will pull the available priorities and statuses from your salesforce.com account.
Note: Like salesforce.com campaign information, this data will be pushed into salesforce.com during a sync, which typically takes place upon an assignment for net new leads, or on set intervals (roughly every 15 minutes) for records that already exist in salesforce.com. If the prospect only exists in Pardot (no lead or contact record in salesforce.com), the task will not be pushed up to salesforce.com unless you assign it (to a user, a queue, a group, or active assignment rule).