Seoul subway line 9 will be open at AM 7, 24 July 2009.
This line will be start Kimpo airport (Southwest of Seoul) thru Sinnonhyeon, end will be Bangi (Southeast of Seoul).
24 July, will open just from Kimpo airport to Sinnonhyeon. another section will be extend later.
This line is expected useful access to Kangnam area of Seoul from western Seoul.
The basic fare is 900 won, the same as existing subway line.
I will update Seoul subway map with line 9 pretty soon.
Reference Site : Seoul Metro 9
(Site will support English, but not now. I found link for English, but not word yet)