That's pretty easy, unless your job is laying out pages using Quark Xpress or InDesign. I'm pretty confident that such things won't be done by a tablet anytime soon.
However, being on vacation, I'm kinda doing that aside from typing this. I can type hella fast on a keyboard, which is why I'm doing that. But I could easily just use my iPad for the entire week. My iMac has pretty much become a machine to back things up (photos, music, apps) and use for the heavy-duty stuff like above applications and HandBrake.
I don't think a lot of us will ever be able to use just a tablet. Maybe if you never used a computer otherwise and over-the-air updates come, sure. But for people like me with a crapload of documents and other files I keep on here for whatever reason, not to mention the gigabytes of photos, music and videos, it just won't happen. Any remote storage solution would be crazy expensive compared to the 3 GB I have here spread across a few hard disks. It's also much faster to access a bunch of those pictures locally than to rely on a 6 Mbps DSL connection.