Here's the fulcrum on which my opinion balances - was it the street sign which first named these heroes as "the seven in heaven" or was that a sobriquet that had already been in use prior to it's adoption as a street sign?
In answer to my own question...
http://www.flickr.com/photos/triborough/4672385210/
http://fallenbrothers.com/community/archive/index.php/t-1874.html
It appears that these firefighters were dubbed the "Seven in Heaven" long before the state recognised them.
As their flack has already said about San Francisco "Besides, that’s naming a city after a person, not after an idea or a religious precept."
The city is naming a Street after a group of people not a religious idea or precept. The fact that the group have been dubbed with a name with religious conotations is not the work of the state. Suggesitons for alternative names are rather moot at this stage.
I therefore don't expect that the New York Atheists would win their proposed suit though IANAL. I suspect that they know this too and will simply accept the publicity that has come their way from the initial complaint and take it no further.
After all publicity would seem to be their main objective.