Apple support giving as anwer "contact your carrier" is unacceptable as this is not a carrier problem, the worldwide scale of the problem proves that, this is not a nano SIM problem for the same reason.
On my side, after sending few emails to Tim Cook I've bee contacted this morning by Apple Singapore, the person asked me few technical thing ( did I check with my local carrier, did I have a nano sim card valid , did I've made a restore ... ) , I've been straight to point and said they should be aware that the problem is worldwide and we have done everything we could to solve the pb on our side, the person seems to admit that and said that they will report to their engineer service with a maximum of information, she said she will call me back begening of next week.
Anyway they must find a solution, if it's not a technical solution then they should propose a comercial solution ... it concerns to many people