I've been waiting for someone to jump on my hurriedly written response, however investment income would make up for the gap anyway... Present value of AGO's future cashflows are a lot more complicated than either of us described, and I wasn't citing a discounted present value with my estimate, but rather future earnings in general.
Assured has managed itself far better than the other monolines, and deserves a lot of credit for this. However, there is a good reason for a healthy discount to adjusted book value. As an example, if the bonds that Assured has wrapped experience annualized credit losses of 5% per year for below investment grade credits, and 25 basis points per year for everything else, it will crush shareholder value.