Question - current state of cross-chain exchange

[murkanovic]

The bitcoin wiki and some threads here describe multiple schemes for cross-chain exchange of coins, some of them have proven problems and some of them seem sound - at least I haven't found any problems published.
I'd be grateful for few pointers:
- what's the best published method at the moment? tiernolan's?
- are there any altcoins (besides exocoin) supporting some version of cross-chain trading without external components? with oracles?
- anyone publicly working on it or every dev scratching their own itch?

Thanks in advance!