As was done with date filtering this year, we desperately need universal source filtering in reports. I should be able to filter a report on any source—blogs, landing pages, URL Start—on any report and as a dashboard filter. Any source, any page-based report, any dashboard.
For example: "Session bounce rate, average duration, and page view totals by source" is a very simple, useful report but the only filter options are Analytics View and Device Type. Why not Blog? Why not URL Begins? And since Analytics View inconceivably only includes data from when you created the view (it's not like you don't have the page data already) it's not always valuable.
Please make source filtering universal.