Hmm, glad I read this thread... I happen to work for a firm that has multiple machines for attaching chips, floating BGA chips, etc. We do warranty repair, mostly for the largest networking firms. I have friends in the engineering department who could swap the chips in a minute or two.
Of course the biggest problem is getting the chip. Since our clients are in a different field there is no way we would stock sat tuner chips. However, I might be able to request samples and have a legitimate possibility of receiving them.
Frankly I'm amazed Dallas Semi doesn't do single piece orders. I have no problem spending $30-40 per chip since I already know they would fix the problem.
Also, something else to think about... Typically vendors develop products that are pin-compatible with their competitors. This allows multi-sourcing components which is something required by most large electronics firms.
It could be that tuner chips from other vendors would work equally well. If anyone has spare DirecTV receivers from a similar time period (mid 2000 through 2001) they could try cannibalizing the part.
Otherwise I placed a pre-order for an HD Tivo... I could ignore the problem and get by on one tuner for the next few weeks.