My favorite old ranter Dave Kearns (self proclaimed as the old man ranting in the corner) has an article for NetworkWorld, raising the question if meta-directories have any life left in the market.
Although I don't know if meta-directories are dead, they seem to still have a place in the world, I do see an end to this technology in favor or other technologies in the future. The Higgins project is offering a new approach to identity control and management. Virtual Directories offer a solution, you can check out OVD and RadiantOne who both offer meta-directory type functionality. (Although Oracle is not explicit how this use case is deployed using OVD since it requires the purchase of additional products, who knows if Oracle has actually tried this or not - you just buy buy buy (story as usual with Oracle right?) until you get the functionality, I have not tried this deployment use case with Oracle personally, I know that RadiantOne offers this functionality out-of-the-box. )
Jackson Shaw (an excellent source of high-quality information regarding in the IdM space) is the source of Kearn's rant, in his more recent posting Jackson again refers to meta-directories as "dead". Shaw also links to Neil McDonald's presentation at the Gartner's IDAM Summit "Everything You Know About Identity Management Is Wrong".
What is sure is that things are definitely pointing to a big change in how Identity Management projects are deployed. The time seems right for a major move towards a more manageable, higher level of fulfillment of the promises of IdM applications, and less complexity.
Noel Yuhanna, principal analyst with Forrester, has some great ideas where this market is going, pay extra attention to "Information Fabric" and "Information as a Service" papers. It is worth the read if you are planning for the long-term. I have learned a lot from his materials.