On Monday, Microsoft formally ended mainstream support for Windows 7, and while this might be a consumer concern, IT users don't have much to fret about.
First off, extended support ends on January 4, 2020. That's when all patching will cease, just as patches for XP ended last April. That's really the only date of concern, and by that point Microsoft should be one or two operating system generations beyond Windows 10.
Once Microsoft ends mainstream support for an OS and moves it to the extended support phase, you still get the monthly updates and fixes. You just can't call Microsoft for free support anymore. It also means Windows 7 won't receive any new features. For example, DirectX 12, which sounds like a massive revamp to the 3D graphics library for gaming, won't be issued on Windows 7. Only Windows 8.1 and 10 will receive it.
The lack of new features is debatable. For instance, Windows 7 does not support 4K resolution monitors, but Windows 8.1 does and Windows 10 will. Is this an issue for you? Then an upgrade is in order.
For enterprise users, it's business as usual. Microsoft service and support contracts don't change. The only impact on IT will be the lack of new feature support. I would think most IT shops have already made a decision on missing features from Windows 7, like 4K resolution or DirectX12, and made the move to Windows 8.1 already.
If there is one area where Microsoft does need to get moving, it has to be service packs. Windows 8.1 still doesn't have one, and Microsoft stopped with just one service pack for Windows 7. The end result in both cases is if you do a reinstall, you have to spend a whole lot of time running Windows Update to get patches, and then patches of patches.
The process will be long and tedious, and users could be spared the hassle with downloadable DVD ISOs that contain just a rollup of fixes. Windows 7's service pack dates back to 2011. That's a lot of fixes to download. However, at this point, I am not holding my breath. Windows 8.1 might get a rollup service pack, but that would be it.