Adamstown is further west, you can see it here in birdseye:
http://maps.live.com/default.aspx?v=...cl=1&encType=1
Like they are currently doing with Howth Junction / Donaghmede, Clondalkin / Fonthill might be a temporary name with Fonthill the eventual name?
Considering the village of Clondalkin is south of the train station and is set to have its own Metro West stop down the line I would have assumed that calling the rail station 'Fonthill' was the most logical choice for IE.