It's long past time to update this.....
Ceton's InfiniTV 4 is in production (albeit at a limited pace) and shipping - they started shipping product in late September. They're still (as of this writing) filling backorders; but, they are available (ish.) And, it's a great little peice of kit.
SiliconDust is moving towards production of their HDHomerun Prime. This will actually be a 3-stream CableCARD tuner (still network-connected, as this is how SD does.) Current expectations are that they'll be made available for sale in late Q2 - sometime-in-Q3 2011 (best guess from several knowledgable sources, as SD is currently working on CableLabs certification.)
Hauppauge will be partnering with SD for their hardware. The current speculation is that this will be a 2-stream (possibility of 3-stream) tuner, and will (as Hauppauge often does) be a USB-connected tuner.
Availability at retail is likely to roughly coincide with SiliconDust shipping their tuners.