now you will get nothing from Singapore or will not see any change on ecas.
Just keep accumulate your relation evidence and proofs for on coming interview.
I have one friend his wife is interview list. Still his wife did not receive second letter if i will inform.
Here is his time line
Singapore received PR Application Jan 05, 2011
Received Interview letter dated Oct 15, 2011 and received Oct 29, 2011.
I wish you good luck for TRV application and when apply make it well organize.
I hope and wish some news from Singapore after their holiday.