Nature article suggested, is that it would be much more efficient and reliable for ETIs to send us messages wrapped-up in hardware containers. Radio signals tend to degrade and disperse over long distances, and it would significantly more efficient to send probes.
Okay, sure. Makes a lot of sense, right?
Well, then where are all the probes? Hell, given the fact that the Galaxy is over 12Gyr old, and that complex life could have originated as long ago as 9Gyr (see Lineweaver), the Galaxy should be covered in these supposed message probes. Given the possibility of self-replicating data probes (a glaring oversight in this study), there should be more probes in the Galaxy than there are stars.
More to the point, given the extreme timescales in discussion and the strong possibility of molecular nanotechnology, why don't ETIs just send over themselves via Von Neumann probes?
In other words, this study, like so many others, misses the point about ETIs altogether. The work of SETI is important, but only insofar as a) it will continue to provide us with evidence which shows us that nobody's out there (yes, yes, I know, absence of evidence is not evidence of absence, but in this case it's an interesting data point that we have to go on), and b) we have little choice but to hope that we're not alone and that we're living in a linearly interesting point in universal history when ETIs first start to branch out into the Galaxy (i.e. we're alive during the opening salvo of a universal phase transition for intelligence).
But ultimately, until SETI and other researchers start talking in a sensible language about our situation, and start addressing the obvious hard problems about intelligent life in the Galaxy, I will be less than interested.