Before wading in, I'll throw out a request for anybody with a good calculator or spreadsheet (it's easy to find some, harder to find some I have faith in) for answering the "sell or keep and rent?" question for a house you're no longer living in...
We've just moved, and were working under the assumption that if we can, that we should keep the old house and rent it out. It's in inner SE Portland, and thus an area that's likely to see only increasing demand over the coming years, regardless of the general ebb and flow of the market. It may fall from it's current value with a "market correction," but it would seem set to become more valuable over the long haul.
However, we had it so filed as a "no brainer" that we only just did a little cocktail napkin math and realized that between mortgage, taxes, and property management fees, we probably wouldn't be collecting enough on the projected rent to stay much ahead of maintenance costs, if at all. We thought we were being thoroughly conservative by saying to ourselves "We don't expect to make any money on rent, just for the house to take care of its own expenses." It turns out it's reasonably likely to fail to do so.
Certainly, it'll be paid off in the middling future, at which point it'll pay for its own maintenance and then some. Which exposes that whole question of whether it's relevant that the house won't cover its own costs. If we paid it off instead of investing elsewhere, the cost of running the house would remain the same, and the rent would remain the same. It's really a question of the total wins/losses over the full term.
Which sort of brings me back to the search for a calculator. When we pick, say, 20 years out, how does this pencil out, so we can compare it to other investments? Real estate feels generally solid in the long run, but even farming out the management we have the worry of getting a bad tenant and winding up with damage or legal wrangling.