This is basically the APM program in Google. Google stopped hiring PMs without a technical background (either CS coursework, or professional experience as an engineer) in 2008, because they found that the PMs they did hire with no technical experience universally sucked.

They also have (had? it's been 2 years since I was there) an active rotation program between eng and PM roles, with the opportunity to transition permanently. A number of my friends did it; I'd seriously considered it, but my manager was willing to let me do PM-type roles without formally switching job titles.