Overview document – Summary given at Posipol 08 workshop by J. Clarke.
Target R&D: Best status overview can be found here. (Some of the material is out of date but the essence is unchanged.)
Flux Concentrator/Optical Matching Devise: For summary of challenges/status see (for example) presentation to positron source collaboration meeting (Daresbury Oct 08) by J. Gronberg.
Helical Undulator: Status of full 4m prototype R&D can be found here.
“Conventional” (think-target) proposal and summary of associated studies (M. Kuriki) can be found here.
Proposed KEK R&D for BN windows and liquid lead targets (J. Urakawa) can be found here.
Compton-based polarised positron source: a good overall summary can be found (for example) here in the presentation by T. Omori. A related presentation on the status of phase space stacking in the damping ring by F. Zimmermann can be found here.