You'll find the scans at
http://planetbattlefield.gamespy.com/As for mod tools, take a look at BF1942. No mod tools at all. Then some geniuses in the community managed to "crack" the BF42 file formats, RFA and standardmesh, resulting first in the Kubelchopper and Parallel World, and from there on Desert Combat. Dice quickly noticed its success and hired these community members to make "official" mod tools. Basically they just ran the same mod tools by quality control and had some user friendliness added. As well as BF42 v1.2 ( ? ) adding support for custom mod folders.
The reason this couldn't be done with BFBC2 is that the content is compiled to binary format for fast on the go loading among many other limitations in the engine itself (no dedicated server files, backend stuff mostly).
If BF3 uses uncompiled content, or includes the uncompiled content + compiler, together with a relatively unrestricted backend, then modding may be possible even without official mod tools.
So basically, we can't predict how the modding scene will be for BF3 until we actually get a look at its files. Could be earlier than expected, could be never, or somewhere inbetween.