I think financial industry programmers are at the leading edge of this phenomenon (much like quants were the leading edge of programmers being paid for value rather than for hours), because they're the programmers who can most easily demonstrate that their code directly made a company millions. They're not the end of it by a long shot. Take A/B testing, analytics, conversion optimization, etc. If you are good at thes…
I'm really curious about non-startup work models that would encourage this. So far, the easiest path would seem to be via consulting, where you sold your services as business services that happened to be software-based rather than as a "warm body" to staff some open slot somewhere.
It seems that overall, startups are probably lower expected value to the early employees in pure financial terms than having compensation tied to measured results for work done for some other company.
I remember essays by both PG and Joel that mentioned the "value effect", PG talking about a "monster of productivity" hacker who added a bunch of value to Viaweb in a single day and in Joel's case, a summer intern who (I vaguely recall) suggested and then built the joelonsoftware jobs board.
I think fogcreek offered the intern some type of stock option bonus for joining fulltime. I don't remember if the Viaweb hacker got something or already had equity of some sort.