Good news, folks.
I'd hit the same roadblocks as above, reaching the 'Couldn't Load XPCOM' error after a successful install (Thank you, Jonathan Métillon). The solution though, is described at the bottom of this page:
http://appdb.winehq.org/objectManage...estingId=18654 (courtesy of a saint called Xin).
At issue are two missing windows files:
By googling the file name, I found options that allow you to download those two files. That is what I did, though if you have a windows machine, you can install Adwords Editor on it, then look in c:/Windows/system32. Once you have these files, then:
...copy them to .wine/drive_c/windows/system32 under your home director [Note that on my computer, I had to copy them to /home/username/.wine/dosdevices/c:/windows/system32 ]
6) start winecfg [I just type winecfg in terminal]
7) click on libraries tab. Add those two libraries. Set to 'native,builtin'. When adding libraries, simple type in the name(without .dll) and click on add.
8) try 'wine adwords_editor.exe' again, and after 10 seconds of loading, it should work!
Also note that in terminal, I had to change directory to /home/username/.wine/dosdevices/c:/Program Files/Google/Google AdWords Editor before typing 'wine adwords_editor.exe' but by this point, the Adwords Editor entry under Wine in my Main Menu was working fine.
I am running Ubuntu 9.04 and using Adwords Editor 7.0.
Thanks to everyone above for helping me figure this out.