While the official eBay Windows Phone app is still available and working, an updated message on the app's webpage shows that could change very soon.
The webpage itself now has a message that states:
Starting September 30th, the eBay App for Windows will no longer be available. You can still shop on eBay by visiting us at www.ebay.com from your browser.
Despite what that message stated, when we downloaded the app from the Windows Store just a few minutes ago, we found that it works just fine. However, if this note is any indication, it may just be a matter of time before eBay decides to make the app unusable. We will update this post if we learn more about this situation.
Thanks to everyone for the tips!