Got my 100K...the problem now is how to spend them. Can I use BA flights on AA or other One World partners? The flights to (or via) London carry absolutely ridiculous taxes...

Among other factors, it seems to depend on where you start out from. I have noticed that from Brazil and Chile these charges seem to disappear, even using BA flights through LHR issued by BA. It also depends on what airline you use -- LAN seems to have few charges even when issued via BA. There must be people here on FT who know the full set of rules.

ThePointsGuy is your friend - click on his British Airways links on the right hand side of the page for a fairly complete education...He wrote a 10-part series on the subject of how to use BA miles

Not been following this thread for quite a while so apologies if this data point is irrelevant:

Made 241 booking last November, canceled BA card in December and travel occurred one week ago from today BOS-LHR-FRA. I checked in online and no request was made at bag drop to see my card, so it was fine to book travel using the voucher and then cancel the card before travel in my case.

I'm sad I missed this offer. Any chance it will come up again early next year? Guesses on the Month?

yeah, me too. just found the 50k link and thought that was a good deal until i stumbled upon this...

odds????
 

What are the odds Chase will run this exact same promotion, 100,000 BA bonus miles, in April 2012 for the fourth consecutive year?

50/50

Who knows, one of the bloggers said there were rumors last fall that it would be coming back. I would think some type of better offer has to be in the works, as the 50k has been there forever. Also they need to find someway to continue to promote their switch over to avios points.