It's never too late to update. Blizzard have released patch 1.14a for Diablo 2, 16 years after its 2000 release date, to bring it in line with modern machiens and make further development easier in the future. This is the end product of a job posting that was listed by Blizzard a few months back, looking for someone to bring these older games up to modern standards.
We wouldn't want to lose some of the best PC games ever, so we're all for preserving them like this.
The update's main focus is to get Diablo 2 running natively on Windows 7, 8 and 10 without the need for XP mode. More importantly, it should now work on OSX for the first time in ten years, since the switch from Power PC architecture to the current one. Some of these updates are still being applied to servers, and may not be available until later in the day.
The official post also makes mention of improvements to hacking detection and anti-cheat services. "There's still work to be done, but we’re making improvements every day" it says, which will come as sharp relief to the hundreds still regularly logging in to Diablo 2 who are a bit sick of getting killed by hackers.
Perhaps more importantly, Blizzard also stress that this is just the beginning. Now that they've got the game working on modern architecture, they'll be looking at other ways to improve it. Chances are it's a small team - possibly just the single individual that was advertised for previously - so development will be slow. In Blizzard style, even the decade-and-a-half old Diablo 2 is selling for $9.99 on the Battle.net store, so it can support itself if people get back into it, but mostly you would assume this is a passion, non-profit project to keep some of their older fans good will.
Next, I'd expect to see Diablo 2 and other classic games added to the Bnet launcher so they're more visible, now that they're working on more machines. Community reaction has been positive, although many of the tools they've been using for a long time have now broken in the wake of the patch changing so much code.