I've spent just over three years as a member of the diaspora, leaving after grad school to take a job in Baltimore; I'm also someone who would love to boomerang home and am searching for opportunities to do so. It seems my - and maybe most of the diaspora's - best opportunity is to seek employment with a company that has taken advantage of the latest networking technologies and is abandoning the concept of being located in one specific place.
A friend of mine recently was hired by a company based in St. Louis, but she's never moved from Baltimore. She set up a home office and the company remotely linked her to its internal networking systems (similarly, its chief IT man is in New Orleans). She loves it.
I think we'll see more companies embracing this concept as they realize that 1) today's technology makes it easy to have a virtual office and 2) it's easier to hire and retain talent if you let them live where they want. We of the diaspora who long to return should be seeking out these companies.
What could you do in order to pave the way for your return to Pittsburgh? That the current regional economic climate is unable to support boomerang migrant demands isn't a secret. The idea is to expand Pittsburgh's job market to other regions currently thriving but desperately seeking the kind of talent that could telecommute.
If you are wondering how you might get into such a line of work, start reading the Freelancers Union blog. The prospect of freelancing might scare you, but at least you can begin to figure out the kind of career that lends itself to geographic labor mobility and allow you to move to Pittsburgh.
What Pittsburgh should do is build the kind of infrastructure that would cater to these economic nomads. Also, the region could offer to help retrain members of the Burgh Diaspora (who want to come home) to become freelancers, entrepreneurs, or telecommuters. If you are curious about the kind of policy that would promote boomerang labor mobility, see the Freelancers Union post about the Hamilton Project at the Brookings Institution.