So from what ive read-
the current theory from where exactly those lionfish off the florida coast originated is unclear, however, the current working hypothesis is from a release of 8 fish from a hobbyist aquarium due to hurricane andrew. Mitchondrial DNA analysis from over 100 lion fish has shown 2 invasive lionfish species (P Volitans, P Miles), that the examined fish were all derived from a few founder fish (most likely the 7 or so released from the aquarium) and these fish originated from the indo-Pacific. I've not read or heard anything about a N.O release of lions unless that data are w/in the last few months. The atlantic lionfish are growing larger and have a higher population density than their S Pacific counterparts (15" Vs 18" SL, and 80fish/hectare Vs 393+/- 144 f/h)
The unfortunate part is that the lionfish's natural predators are not found in the atlantic waters, also indo-pacific lionfish are cannibals with adult lions consuming small lions, this appears one way they keep populations down, however in the Atlantic they appear not to be doing this as food resources are very abundant.
Lastly, i was in Bermuda 3 months ago and one restaurant had lionfish tempura which was amazing (taste like a light flaky grouper) and another resturant had coconut encrusted lionfish w/ a mango salsa- also very tasty. I have to admit as much as i love lionfish- its definitely an eating fish.