Well, BitBoys have canned their projects at least twice in the past... once because they didn't have a manufacturing partner and another because their project was already obsolete before they were ready to make their first silicon attempt.
For Matrox, I heard the rumor from one of Matrox's engineers at a carreer fair about a year ago. With the major 3D chip manufacturers being as agressive as they are, how can one seriously expect a semi-retired player who hasn't had significant experience for the last two or so years to come back in full force?
(you can expect terrific 2D output from Matrox since their video cards are also meant to accompany >$1000 professional digital video editing kits - which is far more profitable than their PC video card business.)
For Trident, if they don't have anything on the way, they'll probably die or be bought by either ATI, nVidia or S3 for their mobile market share.
Of what's left, only S3 and STM are substantially more than vaporware since 3D is in their core product lineup and they have a market share to protect.
How will all this turn out? We'll should have most of the answers by this time next year.
Huzza : if you go check the "Image Quality" thread, you'll see that my "shit128" can do PJ64 quite decently. Yes, Link has white clothes but that's not the end of the world - almost everything else is perfect.