From the contract one agrees to when purchasing these bonds:
"Reserved Rights
Issuer reserves the following rights:
1. To issue additional shares as the market demands
2. To buy back shares at any time within the listed parameters
[...]
Buyback Rights
The issuer reserves the right to buy back bonds at a price equal to 110% of the highest price the asset was traded for over the prior 7 days or 200 times the value of the most recent dividend.
"
TAT will keep it going as long as possible. We'll see what happens to the difficulty. At a certain point price/MH will meet with asicminer. Until then I'm pretty happy collecting 3x more divs a week.
No, TAT will keep it going as long as it is profitable. This is a bond, not a charity. The second difficulty rises to the point where his AM shares don't pay out enough to cover the coupon payments, he'll buy back the bonds, most certainly at 200x the dividend, which will be quite small by that point, leaving investors with a loss (lets be honest, if AM shares aren't putting out, this 1 Mh/s bond isn't going to be putting out squat).
The 200x buyback clause is the reason this bond is extremely risky, and in a rational, informed market, the price differential between this bond and others such as JAH on BitFunder or PAJKA on BTC-TC should reflect that.