that song was one of the best battle musics i've heard. great eps. too btw.
it's definitely not on the osts. some have asked about this particular battle theme in the past and one solution was to try and rip the audio from the eps and encode it into a form where it could be listened too. (i don't know about that or how it will work) so anyhow there's no ETA to the OST 3 but you can check cdjapan <- they have all the latest releases on jpop, anime musics. searched under naruto and found that the next cd will possibly be the naruto movie ost.
here's a link http://www.cdjapan.co.jp/search.html...ep=50&sub=