Some ID shops are picking up Interaction Design–usually specific to product interaction design. But the VAST majority of it is done by pure-play web-design shops or software development shops that include iD as a sub-specialty. Razorfish, Sapient, Microsoft etc…
In my experience, iD is made up of about…
5% Industrial Designers
25% Graphic Designers/Media Designers
30% Software Engineers
10% HCI or HF professionals
30% Self-taught
You might be misled about what Interaction Design is really about. It’s quite large and has been around for quite some time. The specific references you make are more about the experimental side of iD–a tiny niche but a lot of wow-factor.