Grishka - I think it's not so much that the programmers couldn't agree on a standard, as that there wasn't a real standard to agree to, and discussions on the 2.0 draft just went on and on. I hope now that Chris Walshaw is back at the helm that he will make final decisions on a standard based on the various discussions and that programmers will start to implement that standard.
I've started looking at some of the programs listed on the abcnotation software page. Many are just wrappers for abcm2ps/abc2midi or similar, so that cuts down the number of packages to look at.