I remember watching Adam Back's talk about this concept when he was in Israel at a meeting I think sponsored by Meni Rosenfeld.
Request for comments
http://voxelsoft.com/dev/sumcoin.pdf
CT and Anon MiniChain in one coin? Impressive tech and elegant implementation! Do want.
Any thoughts on which PoW is a good fit? My favorite ATM is BBR's Wild Keccak (http://boolberry.com/files/Block_Chain_Based_Proof_of_Work.pdf).
I see Coloured Coins aren't compatible. If implemented independently, are there more trade-offs with other trendy functions like CIYAM's AT, OP_RETURN, or CHECKLOCKTIMEVERIFY? What about proof of stake?
If the Monero folk decide to put Sumcoin under their hood, would you help the core devs with integration?