The ability to work while at Disney is the main reason I get to go so frequently! (Cell phone w/email capability is another "must"--)
I've had one trip when Disney's system would not let me hook up to the internet...the IT people came (they told me I didn't need to be in the room) when over-the-phone troubleshooting didn't help, and left me a note saying their laptop worked perfectly. Unfortunately, they didn't leave their laptop for me to use, and the system would not hook mine up to the net (using their cable)...
But I have an aircard as my "back-up" and it worked just fine...it was a short, weekend trip so it wasn't a "crisis" and I didn't follow up any further...my laptop works just fine at every other off-site place I've used it (3 other hotels, airport)...
It does make a me a tad nervous about my upcoming trip--but out of 25 trips, I've only had the one where I couldn't make the internet connection work ...
And the aircard is a perfectly acceptable alternative, so long as I don't have to use it full-time every trip...
I've worked "full-time" a number of times...but much of my work I can (and do) do well before my family/guests awaken, or late-ish at night (reports, memos, etc. can be written "off-hours")...
So yes, I can and do work (a lot) from Disney--and like a PP, I'd FAR rather do that than not be able to go (or stay as long as I'd like)...