That information is in error. PC Magazine would have been well-advised to come here to AVS Forum and do a little research before publishing that.
All that is happening on July 1 is that cable companies can no longer place into service NEW (unused) set-top boxes without separable authentication (CableCard). They can, however, place into service, USED set-top boxes without separable authentication. Customers are not entitled to demand a new box. As long as they have used boxes to place back into service, they can continue to place them back in service.
Comcast actually ran some sweetheart promotions this Spring to put as many of the previous-generation boxes into customer homes as they could before the deadline (and from many reports, they were quite successful, running out of boxes in some areas). These were generally three month promotions, at the end of which it is likely that many of these boxes would be returned to Comcast, at which time Comcast can redeploy these boxes at the regular price.
Eventually, however, due primarily to the fact that customers will want more and more set-top boxes as time goes on, they will need to deploy NEW boxes to the field, and so the box manufacturers have redesigned their existing products to support CableCard. For Motorola, they're replacing the DCT-series with the DCH-series. As far as we know now, the only difference between the two series is that the DCH-series has CableCard support -- nothing else.