The new date slicer is awesome, but it would be so nice if you could set a dynamic date selection instead of a static. With a static filter the user will always have to set the dates before the saved report makes sense - especially as the report gets older. Dynamic options could be YTD, QTD, MTD, WTD, Today, This Year, This Quarter, This Month, This Week and so on.
We just shipped a preview of the new relative date slicer in the May release of Power BI Desktop. Learn more about it here: https://powerbi.microsoft.com/en-us/blog/power-bi-desktop-may-feature-summary/
Amuses me that BI reports are consistently built with From and To date prompts even when the report is titled something like "xxx Monthly Report". 99.9% of the time users always put in the first of the month to the last day of the month, and run the report at 9am on the ?th day of the subsequent month. Relative date filters make life a lot easier for everyone. I would add previous periods to the list of options.
This is easily achievable with custom report date attributes. For example, add a column to your date table named ReportMonth. When processing your date table always make ReportMonth equal to MonthName, except for the current month which has a value of "Current". Then save your reports with "Current" in the ReportMonth filter. Every time you refresh your report will be pointing to the current month. You can use this same method for other types of reporting periods.