Total distance from Kuala Lumpur to Singapore is about 350km. According to Prime Minister Lee Hsien Loong, high speed rail will connect these two cities by 90 mins. So, average speed of the high speed train is estimated to be 233km/h.
By the way
http://bursastocktalk.blogspot.jp/2012/04/kl-singapore-high-speed-rail.html
This website says estimated stations are
Singapore, Johor Bahru, Batu Pahat, Muar, Melaka, Seremban, KLIA,and Kuala Lumpur
But, in order to keep travel time within 90 mins, fastest trains should skip some stations.
I expect that those trains will stop at Johor Bahru, Seremban, KLIA.
If this high speed rail runs near Kuala Lumpur International Airport, Airport Express will lose its role. How do they think about this?