I'd be interested in other responses to this from other folks.
My one question is whether you are asking about making dashboards that are visually interesting or are you talking about making a really functional dashboard?
Excel can do some pretty amazing things. And because our REST is open, it isn't too hard to do.
Take a look at this document and download the Excel doc at the end.
You'll have to enable macros on the document but if you right click in any cell (after enabling macros) you'll see an option to "Generate REST".
Click on that and it will walk you through the steps of creating a REST url right in Excel.
When you are done, right click and choose "Run Queries" and it will create a new spreadsheet for the rest urls you created.
All the code behind this is open and easy to view and edit. Just press Alt - F11 and it will show you the macro code and the user interface behind it.
Being able to browser through your Webtrends data on the fly like that in Excel alone should impress your boss.
Taking the example in this document, I'm sure you can imagine building your own date selector maybe like this:
Here is a snippet of a screenshot of a dashboard made by our DMO (Digital Marketing Optimization) team which builds amazing dashboards and caters the data to the organization. They are obviously really good at this but it at least shows you an idea of what kinds of relevant metrics you may be interested in.