It turned out that Starfleet was WRONG to team up with the Borg and that the Borg actually persecuted Species 8472 instead of the other way around. 8472 debuted as this HUGE threat that was so powerful it could take on THE BORG (their catchphrase was "The Weak Will Perish" ) and they basically make peace with Janeway and Company in a one off episode that sucked. I like it when villains have different facets (they've shown this with the Dominion and even the Borg itself) but they COMPLETELY gutted the entire concept of the aliens in one lame episode.