I see computing becoming more decentralised in the future instead of centralising, so I think that hosting will remain in data centers, but by 2010 I say it would cost next to nothing for a do-it-yourself becuase an internet connection would be a necessity.
I sincerely doubt it. Everything is cyclic; technology is no different. We went from "terminalized" mainframes and mini's to decentralized, replaceable units and now we're headed back towards a more central system offering virtual controls.
While having a wireless loop broadband access account will be far more ubiquitous, less consumers will require serving architectures in the home. Permit me to explain.
While bandwidth will increase AND whereas the use of various broadband wireless technologies (terrestrial loop, GSM, WWAN, etc.) will replace wired networking, becoming the de facto standard for *access*, the need for serving will be reduced too all but extreme hobbyists.
Middleware will permit an easily understood layer of abstraction between applications and end-users. The use of virtual environments will eventually become the norm; adding new customers will take seconds and require no manual intervention and will be the equivalent of buying a new box, loading your OS of choice, building out the applications and altering DNS records to point at the various offerings.
This will lower overhead (man-hours) and increase productivity to such a degree that the cost for an average small business environment will be trivial. Certainly compared to that of actually accomplishing said work on-site.
That's how I see it anyway.

"It's always a long day, 86,400 won't fit into a short."