I for one will probably continue to use taxis. They are relatively hassle free and it saves humping large luggage around on a train and up escalators and stairs.
why would you keep using taxis??? It will only take 15 minutes to the city and only cost 150bht. Personally, I travel quite light, and the luggage I do have can be wheeled. I'm sure there will be escalators taking you to the platform anyway.
I usually get a taxi to my condo in thonglor, which takes MUCH more than 15 minutes, and costs a lot more than 150bht, so I am really looking forward to the rail link. Also, I would much prefer to enjoy a ride on a new train than have to look up each time the taxi driver ducks and weaves through traffic..