The first thing that you should keep in mind when watching this video of Steve Jobs demonstrating the features of NeXTSTEP 3 [YouTube — 35 minutes, 8 seconds] is that it was shot in 1992. Back then, the competing mainstream operating systems were System 7 on the Mac (George ran it on his IIvx, I ran it on my 660AV), and Wintel users could choose from Windows 3.1, OS/2 2.0 and the most popular one, the sad but ubiquitous MS-DOS 5.0.
If you want to see how far ahead of its time NeXTSTEP was, watch the video over your lunch break. In the first two-thirds of the video, Steve demonstrates the dock, the Mail app, dragging and dropping attachments directly into email messages, smooth window dragging, voice annotations, WYSIWYG word processing, index-based file search, seamless browsing of other directories on machines on the network and object linking. The machine appears to respond snappily, even though its processor ran around 33MHz and it had a only a few megabytes of RAM.
Being a developer, the bit that gets me the most starts at the 23:10 mark, when Steve uses Interface Builder (which lives on in the Mac OS X developer toolkit) to cobble together an client app that connects to NeXT's Sybase-based employee database and provides a master/detail view of employees, displaying both text and photo data. Windows developers wouldn't have this sort of toll available to them until 1995 when Borland released Delphi 1 and Microsoft pushed out version 4 of Visual Basic (I didn't think VB really got useful until version 5 in 1997). Mac users would have to wait even longer for REALBasic to give them the same capability.
In addition to the tech time travel aspect, the video also gives us a look at Steve's years “in the wilderness”: a skinnier, clean-shaven, IBM-ish shirt-and-tie guy honing that “presentation Zen” for which he is known today. We expect him to take shots at Microsoft's offering, but seeing him make jabs at Apple is priceless.
The video's inspired a fair bit of commentary: see these Reddit comments as well as these blog entries on programming musings and Rixstep.