I think the Eye of Terror is a safe place. I sincerely doubt that the Hive Mind could overpower a region so saturated with the might of Chaos. As long as we don't step out of our warp rift, we will be fine.
I guess they'll get their chance to prove their worth once we march on Arkhona and raid their little hives.
You underestimate the power of the dark side... of Chaos! ò.ó *g* But actually, you're right, at least the hive fleet will try to, so there you have it Personally I'm so much looking forward to the PvE part!
I've always had a thing for Tyranids vs Chaos or vs Necrons. With the Imperial Factions, the Eldar, and even the Tau you always have this "desperate noble race fights against overwhelming odds" vibe. With Chaos you have the "Go to the Warp, Bug! I'M gonna kill the good guys!" I fondly remember the imagine of a Bloodthirster battling with a carnifex.
As far as I know managed some Iron Warrior to hijack a Hivefleet, kill the Dominatrix and controlled the Hive Mind (with an Army behind his back, ofcourse) Chaos Nids! Every other Legion/Warband would just fight them, like every other enemy. Some tzeentch Marines would maybe try to get others to fight them.
Funny thing is while immune to mental temptation (so long as the Hive Mind retains it's hold) there is actually no way Tyranids could resist physical corruption without direct Hive Mind psychic intervention. If they went into the Eye of Terror/Screaming Vortex etc. we'd have a lot of Carnifex gone Spawn.
How sentient are the hive minds? Are they able to be corrupted with Greed or Avarice? Able to be whispered to by Slaanesh? Or Ushered into an offer of Nurgle?