arguably, sneila's species album from 2001 could be the first newschool. it was happily played in newschool dj sets and also has that early newschool sound (bright, soft melodies, melodic but not overloaded like later newschool, also not really like pleiadians at all). other contenders are the blissful moments compilation (2003), ethereal - anima mundi (2003) and ypsilon 5 (2004; it's pure newschool imho), sky input of course, va - pure planet (2004; this one includes sneila as well as goasia). these along with apsara (2005) really defined the newschool sound (of the time) for me (well, maybe not no much sky input — filteria has his own unique style). a sound that was dominent until daze and arcana (which broadened the scope of newschool). i miss the "old newschool" nowadays. i much prefer it over what's popular in now (morphic resonance, celstial intelligence, ...)
btw: space juice is psytrance rather than goa in my music library ;). but yeah, many tracks from around that time (or a little earlier) are hard to divide into psy or goa. try to classify talamasca - the old school, the tracks from cosmosis' contact album, electric universe's unify album... you'll get different answers from different people :)