Haven't seen any sources except original xevan-ccminer, but it has only cpu-hashing implemented, so writing from scratch basing on algo-description and existing opencl kernel. Anyway, there'll be a choice for BitSend miners. Haven't heard about lyra2z330, should look at it. But AMD miners will drown us all one day, will it be leaving ETH for other coins because of hashrate drop, or will it be leaving ETH after PoS, it will definetely be doom-day for all mining community for a long time, I suppose.

Anyway low speeds of reds on Signatum defended us from them here. With them everything would be much worse.
Lyra2z330 Zoin coin algo. Used to be CPU mining with 300-400Khash per pool till 3-4 days ago. Now top miner makes 1.2Mhash. 10 i5 CPU make 7-8Khash. So you can count.
'll try to make CUDA xaven miner working tonight, but that's hot day and few beers can happen ;-P