ComingSoon.net has recently received word from Moziplussz.hu, a Hungarian film website, with updates on the filming locations for Eragon. Filming for Eragon will begin in late July at Mafilm Studio in Fót, Hungary (near Budapest). Dinotopia: The Series, A Christmas Carol: The Musical and Copying Beethoven (coming this year) were just a few of the movies filmed at the Mafilm Fót Studios.
The Mafilm Fót Studios is not the only place Eragon will be shot at. Eragon will also be filmed at Ság Hill, which is located on west side of Hungary. Scenes will villages, waterfalls, etc. will be shot at Ság Hill. Images from various locations to be used in the Ság Hill filming can be found: here, here, here, here, here, and here.
EDIT: The link issues with the images of the locations has been corrected. You may now view the images. Sorry for the problems.