UPDATE (13-Dec-2013): Microsoft has a fix: http://answers.microsoft.com/en-us/windows/forum/windows8_1-networking/dell-venue-pro-loses-wireless-connection-after/bc8a1426-fdb8-466d-b074-c80a06e70d76 and direct link to update http://www.microsoft.com/en-us/download/details.aspx?id=40755
UPDATE (10-Dec-2013): Updated to include fix for WiFi problems caused by latest Patch Tuesday installs.
My WiFi stopped working on my Dell Venue Pro 8. Uninstalling Microsoft Updates KB2887595 and KB2903939 fixed the problem.
TIP: After uninstalling these updates, you can go back to Windows Update via the method below, scan for updates, then right-click the updates and select Hide this Update so Windows doesn’t repeatedly try to reinstall it.
To do this:
1. On the Start menu, swipe down to All Applications
2. Scroll all the way right and tap Control Panel
3. When Control Panel appears on the desktop, search for Windows Update by typing in the search box, and tap it
4. On the left pane there will be an option for View Installed Updates. Tap it.
5. Find Update for Microsoft Windows (KB2887595) and tap it, then tap Uninstall. If you also have update KB2903939, don’t restart yet. Otherwise, skip to step 7.
6. Find Update for Microsoft Windows (KB2903939) and tap it, then tap Uninstall.
8. Your WiFi should be working again.