They released some information on Twitter, best is probably if you go through it yourself and read what they say there. I do not think that funds are in danger, as the FBI only has control over the domain. They could easily make a new one like 1broker.net and start over with blocking ips from US.
i assume the funds are still secure, but they're under the thumb of the feds. as they said on their twitter, they intend to fully cooperate with the authorities. that basically rules out a btc-e redux where they spin up a new domain and continue business as usual (sans USA customers).
best case scenario is they do it like pokerstars: allow non-USA customers to withdraw and force USA customers to go through a claim system.
but i'm not sure that will happen. it's really at the discretion of the feds.