Avengers Academy 32 was OK. Other than their appearances in AA, I am totally unfamiliar with Juston and his sentinel, so it was hard for me to care when Emma showed up to slag it. Emma-Phoenix seemed rather reasonable about re-programming the sentinel until Juston's rather strange declaration of love for the thing caused Laura to attack Emma. While I liked the previous arc involving the Generation Hope/New X-Men kids, this arc is starting out a little flat. I'll be glad when AA moves past AvX and into the "Final Exam" arc.
Sentinals are sapient(ish) beings. Erasing it's mind or destroying it, the result is the same, Emma's unprovoked attack was nothing less than an attempted murder.
Indeed, Emma's systematic destruction of all the Sentinels on the planet was itself nothing less than genocide. While she has very good reasons for her prejudices, the fact remains that her actions were entirely unethical, and could easily constitute a war crime of epic proportions.
And that brings us to the crux of the matter. Cyclops, Collossus, and Magick, and even Namor are good people with high ideals. Sometimes they make compromises, but their motivations are always positive. Emma, on the other hand, is an amoral bitch who has no high ideals. She does what's best for Emma, the rest of the world can burn for all she cares. Heck, the last time the Pheonix was in town she conspired with Jason Wyngard to mindrape Jean and control her for their own benefit. That plot lead directly to several billion deaths and she never really gave a fuck. She reformed because a cushy and overpaid teaching job was simply safer than supervillainy, not because she believed in Xavier's ideals. Giving her that kind of power is not a good idea.
Cyclops and Colossus will both die for their ideals. They've done it on screen. Magkick and Namor, are also willing to sacrifice themselves when necessary. Emma isn't. If it ever came to be that she would benefit more from destroying the Earth than she would from not destroying it, she wouldn't hesitate for a second.
Previously she was kept in check by the fact that the Earth is where she keeps all of her stuff. Now it just holds the largest collection if her enemies. Somebody needs to kill her before she figures that out.