Are there any 380's flying with fare paying pax at present,
Yes. Just one. Number 003, with Singapore Airways.
if so which routes are they operating?
Only one route. Singapore-Sydney-Singapore daily. It spends about 6 hours in Singapore airport, it has not needed longer maintenance for month and a half since 28t October and it is hoped that it will not need maintenance for a month or more yet.
When is the 380 expected to be a regular visitor to LHR?
The guesses are between January and April. Singapore certainly plans to fly daily SIN-LHR-SIN after it has received 2 more frames, numbers 005 and 006. Daily LHR flights cannot be done with just one plane, so there are speculations about what happens after 005 has arrived and before 006 arrives. Maybe 005 would fly 3 times in a week between SIN-LHR. Or maybe 005 replaces 003 on SIN-SYD while 003 is in maintenance, and SQ only starts flying more than one plane in service when 006 has arrived.