Out of curiosity I googled some of the companies you mentioned.
Here are the results:
AJA - the home page mentions Adobe CS5 and Avid. No mention of FCP.
http://www.aja.com/
Matrox video - the home page mentions "solutions for Avid and Adobe CS5". No mention of FCP.
http://www.matrox.com/video/en/home/
Blackmagic Design - Mentions Adobe CS5. No mention of FCP or Avid MC.
http://www.blackmagic-design.com/?nab=12
Looking at these web pages it's difficult to tell how much investment these companies have in FCP. Are they "all in" as you imply or are they hedging their bets?