The exchange comes from MyPoints. You need to accumulate 20,000 mypoints and then redeem them for 25,000 VacationMiles, which you can then redeem into 25,000 AA Miles. So, if you've already redeemed Mypoints for vacationmiles in 5,000 increments, you're probably out of luck on the 20,000/25,000 bonus.

As far as them being in business--They went public a few months ago, opening at around $15 per share, I believe. The stock later skyrocketed to $97/share and is now around $43, after losing $5 per share today. (symbol MYPT).
As long as their stock stays above $15-20, I can't see them going out of business real soon. Personally, I'm just checking their stock every once in awhile and in the meantime holding on, hoping to reach the 20,000 point level again.