Or this is a big setup by Voldemort. Saying "I must make a Horcrux" out loud is the giveaway; I doubt even Harry's fantasy of a beatable Voldemort would be that stupid.

My guess (conditioned on this not being the mirror) is that Voldemort gave Harry his pouch and wand and then faked weakness to trick Harry into attacking him so that he could kill Harry without violating his prior promise. He resurrected a nearly-immortal Hermione to dissuade Harry from ripping the stars apart in case killing him failed, as part of his defense-in-depth strategy against the prophecy. Since he could have tricked Harry by much simpler means if that were the only goal, he can say in Parseltongue that restoring her counsel is the greater part of his motivation.