Well Apple aftersales were friendly and helpful and have arranged for a replacement to be sent... but the quoted shipping date is 8th March... here's hoping that will jump forward significantly!!
Just got an email saying that my replacement machine has been shipped. Very happy to note that its getting UPS treatment all the way from Shanghai, estimated delivery is Monday - now that's fast! I haven't got the new serial number yet - any idea what week machines are currently shipping, and how they are looking for yellow tinge?