There are a few things you can look at that will give you more info than just "In Progress".
In the Windows Expedited Update Reports under the Reports blade, look at the Update Status and Update SubStatus columns. These provide more details exactly where in the update process a device is currently. If a device is in the Offering OfferReady, a common state, it means the Expedite signal is sent from the service, but the device hasn't yet picked it up. Usually due to low Update Connectivity. Once a download starts, you'll see download, install, and restart required states.
Another place to get more information is the Errors report. Start with Devices / Monitor and bring up the Windows Expedited Updates failures report. The Alerts column will explain any issues we've detected, and clicking on the Alert will provide a flyout with a more helpful description as well as a recommendation for resolving the issue. We are going to be adding more alerts over time to help even more.
Hope this helps,