I first mentioned Blackstone gateways at CFUN, and there has been lots of interest and curiosity ever since. Sean Corfield is already building Blackstone gateways (using the alpha version of the product), and has blogged an overview of how he is using gateways to tie different systems together in a Macromedia in-house application. See http://www.corfield.org/blog/past/2004_06.html#000490.
I presented Blackstone to the Philadelphia user group last night. Some of the attendees had attended CFUN, so I tried to alter the content slightly. This was a rather quiet (almost subdued) group, one of the attendees suggested that that was typical of Philadelphians, but I don't buy that at all. It took some effort, but I was able to wake them up and even get them to display genuine enthusiasm. The session went well, lots of good questions, and even included a somewhat animated debate on which features should be included with CF Standard and which to only include in CF Enterprise (and no, I did not make any commitments here at all, we're still trying to figure it all out).
I drive to NJ and NY shortly for 2 more user group sessions today, and then tomorrow I wrap this segment of the tour in Boston. 3 more to go, and we're within 200 people of our total attendance objective!