You already know by now that Microsoft's Windows 8.1 is mostly fixes, tweaks, and aesthetic changes. It searches more effectively, and if you're already a Windows person, you're probably using Windows 8.1 now since the upgrade is free. (You may be slightly annoyed with Microsoft since Windows 8.1 is basically what Windows 8 should have been the first time around had it been done well, but put that aside for the moment.)
The real news here is that according to Web tracker Net Applications Microsoft's Windows 8.1 has now overtaken Mac OS X for desktop users, making it the fifth most used desktop OS right now. Windows 8.1 alone is only in use on around 2.6% of desktops, but Windows 8 and 8.1 together account for more than 9% of desktops now.
Windows 7 and Windows XP are still outpacing the Windows 8 and Windows 8.1 editions by far, of course, especially among businesses which tend to be slow to change. Windows 7 is currently used by more than 46% of desktop systems, and Windows XP is in use on more than 31% of desktop units.
Microsoft won't let that happen forever, though, and is eliminating Windows XP support in Spring of 2014 as part of its ongoing effort to force the cattle into their preferred OS chute. It seems doubtful that they'll do much for Vista which is in use on just over 3 and a half percent of desktops, but with these gains for Windows 8 and Windows 8.1, Microsoft's latest scheme seems to be a success thus far.