Are there any successful examples of companies that target specific niches relating to applications -- such as companies that specialize in hosting Trac/SVN repositories, companies that specialize in CMS hosting in a few different flavors -- and ONLY offer this service?

I'm looking at the kind of hosting I'm doing for consulting clients, and things seem to be heading in this direction for me, since I refuse to try to compete on volume with shared hosting, and I want each client to pay for itself -- no loss leaders for volume. Ideas?

If a company is realy serious about hosting a critical App, they are going to use dedicated servers or their own DC. Imagine the importance of a critical App for a company that relies completely on this.

I would recommend to try to open your market a little more, but thats a personal suggestion but whatever you choose, good luck on everything ;)

I know that Dream Host includes SVN, but that's all I know. I think most people using SVN and CVS in the open source world will use Google Code or Sourceforge, since they are free. Those doing commercial app development or companies developing their own apps will probably be able to afford their own servers (which they would probably have anyway, for development purposes). I think that might be a difficult space to make money in.

A nice way to add value / get customers might be to develop some automation tools for deploying SVN repositories and CMS applications (ie. I sign up and instantly have a SVN repository setup for me).