About a year ago, my iMac stopped working, I didn't immediately have the funds to replace so had to use my iPad as main computer. I coped, it was possible. Although I was very happy when I got by new macbook.
If your employer provides you with a computer for work, then it is very possible to get by with an iPad as your only personal computer. Don't believe this stuff about the iPad being for media consumption only......absolutely untrue. There are a wide range of productive things that you can do with an iPad that are helpful in your personal life......finances, document management, photo organization and editing.....the list goes on and on. You will need to rely more on cloud storage, but I see that as a good thing over the long hall because all of your documents and photos are synced and accessible from your phone and other devices.
I suspect that many young people graduating from college will not bother purchasing a regular computer, if their employer provides one for work. They will be much more comfortable using mobile operating systems to get stuff done in their personal lives. They will also be much more comfortable with cloud computing and storage.
I've barely used my laptop since I got my rMini about a week ago. Only time I've actually turned on my laptop is to scan a couple of applications for my boyfriend since he is looking for a local job. He's currently an over the road truck driver. And that, could have been done from my ipad.
It will all depend entirely on personal needs. Many things can be done, but can take a lot more work. And some things are just not really possible or ideal.
For example, if you ever use more than 1 application at a time (such as writing an email while looking at a web page), or if you want a larger screen, hard drive storage, USB devices, file storage, user accounts, etc.... You may find it inconvenient. Some web pages won't load properly, and the site may have an app, but it might be limited.
Ultimately, a Surface 2 / Pro 2 would be a far more qualified replacement to a traditional computer as it addresses pretty much all of the shortcomings.