They have a few options available.
1. closed down or just leave the site as seems to be the case.
2. start a fresh.
3. if they had a back up of balances give everyone a percentage share of what is left.

hindsight is a wonderful thing i know but why on earth were back-up of balances ect not made on an hourly basis ?
I feel for everyone. I was one of the ones who lost a lot of BTC's to mybitcoin.com & now this.
I'm gutted.
Now i will make multiple backup copies of my wallets and store them off line.

Update: I'm now unable to login at all now.
Upadte2: I'm able to login again but my payment is still processing since the 5th November.