Identifiers are a topic of ongoing investigation in a variety of contexts, and as more of our activities are driven by network workflows, supply chains and other data flows, they become more important. There are multiple active identifier discussions underway in our community as we speak.
It is this topic that my colleague Stu Weibel is exploring while he is based at the University of Washington this year, doing work, we hope, which will explicate the current state of the art and give some pointers as to sensible directions (and many thanks to the iSchool and to Tony Hey, Corporate VP for Technical Computing, and his colleague Randy Hinrichs at Microsoft, for their collegial support in this endeavor).
Prompted by a post by Sean McGrath on the permanence of URLs (check out the comments), Stu has been thinking about this topic in several posts over on Weibel Lines (here, here and here). Stu makes the point that the promise is more important than the protocol; it is organizational commitment that assures persistence, not a technical fix. For this reason, we can expect to see more identifier services as we move forward.