I would love to see the Usage and Access Logs start to track additional events (in addition to other products - ad hoc analysis, report builder and data workbench) based on user actions - here's a quick list to get started:
What date ranges are selected? Are people analyzing on annual, monthly, weekly, daily levels?
Are segments being used? What segments are being applied?
People accessing/viewing dashboards that are emailed to them
People using the "create a link to this report"
People "adding metrics" to reports - help determine right Default metrics
People looking at Trended vs. Ranked reports
People who "execute a search" on a report to find a specific item
With this data, we are trying to understand the engagement of the interface and this can really be expanded to track all interactions/options within the tool. Right now, the existing set of actions is too limited to truly understand.