when they will release mainnet wallet?
Now that "end of january" passed without a mainnet client, I'm pretty sure that it won't happen at all. Most likely, the "inventors" sold their premined coins already at coinex and dropped the mic.
I bought bch on some exchange before 512666 and transferred to my own wallet, then afterwards transferred back to exchange and sold with a small win. I guess that win is already all I can ever expect to gain from that fork... :-)