The iPad is also well suited for use as a stationary screen, fixed in place for quick access when needed. There are myriad docks, mounts and stands available, many of them useful for technicians and mechanics referencing take-apart guides; for cooking in the kitchen; for musicians who need sheet music displayed; or for power users who need an extra screen.
Netflix works just fine on the old iPad (though you don't get the Retina display newer models offer).
A mini TV
From my own perspective, the first-generation iPad is still great for watching movies and TV shows, listening to podcasts, or, if you don't mind reading on back-lit screens, perusing an ebook. There are plenty of apps on this front, from iBooks to Kindle to Nook to whatever you like.
If your iPad is like mine, you'll find that the battery still holds up really well, and the fact that video is hardware accelerated -- one of the reasons Apple execs pushed for the h.264 video codec -- means there's less drain on the main processor, and less drain on the battery. The full library of videos available online from iTunes to Netflix to Hulu and beyond means there is always something to watch. And if you're going to be away from an Internet connection, you can download movies or TV shows to the iPad and watch them wherever you are.
In concert with an Apple TV-equipped HDTV, the iPad can also stream video to your TV. Actually, I'd be less bullish on the original iPad if it didn't support AirPlay. But since it does, the ability to wirelessly transmit to an Apple TV in the home is a plus in favor of keeping the iPad around.
Hand-me down iPad
The iPad can serve as a hand-me-down device that can grow with your child; there are cases that add bulk (and protection) to the iPad in kid-friendly designs that can be updated as needed. And the wealth of kid-oriented apps in the App Store means it will serve as a learning tool for as long as it's still working.
There's more than just kiddie apps and games; the iPad still has access to content on the completely underrated iTunes U. Apple calls iTunes U "the world's largest online catalog of education content," and this collection of lectures, course materials, books, videos and other assembled materials will help you learn about any topic you choose.