I agree with both Will and Tom on some issues. I do have a hosting plan, and will be providing a hosting package to my customers when we get that far, but I don't intend to do updates to shopping carts myself either as it could be come something that you're stuck doing on a constant basis with no reprieve lol. I am planning though to create their shops for them providing they have a little software knowledge that will allow them to continue to add their own products and such afterward. My reasoning is selfish, I have a shop of my own that I "hope" will take off soon, and will need much time just for that since much of my stuff entails taking hundreds of photos everytime I order lol.
On the other hand, I think Tom that you underestimate the number of people out there that "could" do their own sites, but just don't want to, or have the time to do so to get it all setup. By setting up a site for them and letting them maintain it, they are getting a little of both sides then, they get someone to do the initial build which is 95% of the time consuming issue for them, and yet they can maintain it themselves without having the hassle of sending descriptions and pictures etc. to someone else and waiting on them to do it. I think that works out pretty good myself.
Having said that, if someone were to want a shop that doesn't do a lot of product changes, then yes I would opt to maintain it for them if they want me to, but the large scale lots of changes shops, I think I'll pass that on to them and get CC a little more money by getting the customers to by SCC Pro
Disclaimer: These opinions are subject to change should my old brain decide that it's not as much work later as it seems to be right now LOL.