Self-imposed exile sounds like something Jason would do. It's more in his character than doing so just because Batman says so (but of course he'd be honorable enough to abide by the rules of their duel so maybe). I mean, Gotham is his home too. Moreover, with Lobdell's tendency to humanize characters all sides, I don't think he will make us walk away hating Bruce. Instead of "you killed, get out Jason" it could instead be "get help, Jason". With Superman showing up, I don't know if it has anything with Bruce/Jason, but I certainly hope he saves the HQ from falling on people.