Is there anything else someone in my position can do? I'm about to ask my neighbors if they saw anything. It happened between midnight and ~8 am.
For instance, in Amsterdam (NL) there is a well-known black market for bikes, and when a bike is stolen there is always a good chance of finding it there.
On the contrary, for example in Paris (FR), my advice would be to forget about it — people even steal the heavily-impractical public rental bikes.
General advice for your next bike: take appropriate security precautions (more insecure neighbourhood -> bigger chain), and try to have it look cheap and dirty to discourage thieves.
Consider challenging the insurer's decline of your claim, particularly if the bike was expensive.
I work for an insurance company (not in the UK) and we specifically ask for such easily movable objects to be explicitely registered in the home insurance policy (make, model and in some cases identification numbers), they're otherwise excluded. People must remember to register new purchases (they usually don't), and it's up to the insurance company whether to cover them or not. As part of a bigger (proven/proveable) theft, they might, but usually not as a singular event (too easy to abuse).
Apparently in the UK it's an optional:
http://www.which.co.uk/money/insurance/guides/contents-insur...
Monitor local classifieds ads (craigslist, kijiji, or whatever in your area) about related items. Visit "potential" thiefs. If bike found - agree on price, leave deposit. Come back to "pickup your bike" together with police officer.
All "bike recovery success" stories and "how i screwed my bike thief" stories started exactly like that.
You could try to set up a bait bike and hope they're greedy/stupid enough to do it again.
Also, sorry for your luck.
If you find it, you might be able to either buy it back or contact the police if you had it registered.
EDIT: https://www.taskrabbit.com/oakland-sf-bay-area/t/hit-east-ba...
Won't get this bike back, but this is a problem for millions of people out there....