My understanding is that the bit asset bitJPY has already been created, there is just not enough capital backing it to get it started.
http://www.bitsharesblocks.com/assetsshows all assets and JPY has been there from the beginning (as part of the genesis block)
market opens when 2 conditions are met:
- 51+ delegates publish a price feed for it (not older than 24h) ... currently only 20 delegates do so .. will change soon after the next wallet release IMHO
- 500k BTSX of orders on both sides (ask/bid(short))
once both conditions are met, the market will execute only if both conditions are met after matching orders ..