I've seen the results of some offline testing done with our standard bench testing tools. Tasks validate properly with all the regular applications - specifically, with stock v6.10 and x41g from the installer - so there is nothing to stop the cards being used right away at SETI. We don't have a repeat of the Fermi disaster, thank goodness.
As Mike says, the speed isn't spectacular with the current applications, but there are signs of significant gains with applications specifically written and compiled with the new architecture in mind. As always, it's the combination of hardware and software - especially the software development tools supplied by the manufacturer - which makes the difference, not just hardware on its own.