About 5.1 jailbreak for A5+ devices: it’s not out and I have no clue when it’ll happen. I’m working some hours per week on finding vulns.
But right now we (cdev) have some pieces of a userland jailbreak, but we miss some, and even it we had them all, there’s weeks of work to put them all together in a public ready tool.
pod2g as you noticed referred to A5 devices jailbreak. A4 devices jailbreak is viable to GeoHot’s Limera1n bootrom exploit. They just need to create an untether jailbreak for them.