I have a Keurig machine, and I use the refillable K-cups which I fill with whatever coffee I decide to buy at the grocery store. It's much cheaper than the packaged K-cups, and in my opinion, tastes about the same.
It seems Keurig is tired of 3rd party coffee brands using their system.
"Green Mountain has announced a new anticompetitive plan to maintain its monopoly by redesigning its brewers to lock out competitors’ products. Such lock-out technology cannot be justified based on any purported consumer benefit, and Green Mountain itself has admitted that the lock-out technology is not essential for the new brewers’ function. Like its exclusionary agreements, this lock-out technology is intended to serve anticompetitive and unlawful ends."
Source: TechDirt