I imagine they're just showing off their programs for the platform. Google have been touting Android as an 'open' platform, I doubt they're going to turn back at this stage.
I'm not particularly in the know, but I think it's important to keep in mind that this isn't a "normal" platform release. Honeycomb is still a bit immature, we're not expecting to see shipping devices for another 3-6 months (Motorola is simply saying "Q2" at this point from what I can tell).
It's a bit too early for 3rd party developers to be invited to the party I think.
