So I've managed to do this with symbolic links. I tried (as I said) to do it like here: http://www.mentalfaps.com/blog/2013/08/29/using-yeoman-with-phonegap-and-backbone-dot-js/ But then I noticed that the link was made in the wrong way: So, what I did: (in the Android's project assets dir)
rm -rf www
ln -s <path to angular www folder> www
Now this will create the right link. reopen your eclipse. Refresh the project and you should see a copy of www in the assets folder!
Hope it helps anyone who was having the same problem.