iPhone 4S will be available in Singapore on 28 October. This is the launch date posted on the official Singapore Apple Online Store web page. I reckon the local telcos, especially Singtel will be able to start sell the iPhone 4S on that date too.
You can find out more on the iPhone 4S Singapore launch date at this official Apple web page:
No pricing of the new iPhone 4S in Singapore dollar yet, however, I expected the price of the iPhone 4S without contract to be same as iPhone 4. SGD888 for 16GB and SGD1,048 for the 32GB model.
At the time of writing, there is no news from any of the telcos: Singtel, Starhub or M1 on their official launch date of iPhone 4S in Singapore yet. Meanwhile, we just have to wait for a few more days for the confirmed date and pricing for the iPhone 4S plans.