Time's James Poniewozik, in his Tuned In blog, observes that Discovery Home becomes Planet Green this week. Discovery Home is one of those cable networks that most people probably didn't even realize they have, up there in the upper reaches of their digital cable tier. And this is part of the point Poniewozik tries to make: Discovery Home never established an identity for itself, trying to be "a little cooking, a little home design, a little lifestyle" (all market segments already served by other networks).
The phenomenon of cable network transmutation has been active in the past year or so. At the beginning of this year, Court TV mutated into TruTV; the Outdoor Channel (I think) mutated into Versus; and a little further back TNN (originally The Nashville Network, then in a misguided mutation designed to avoid getting new initials, The National Network) turned into Spike. The phenomenon has even occurred with networks that were arguably even more obscure than Discovery Home, evidenced by the mutation of INHD (a network I liked very much even though I don't have HDTV) into Mojo (a network I have no use for whatsoever).
This kind of cable network transmutation, while probably a sound business strategy (maybe), seems to me to accelerate the increased mushy similarity of cable channels, as every one of them tries to latch onto a (cable-sized) hit like History Channel (in one of the more inexplicable programming choices) has with "Ice Road Truckers." Likely, in most cases, the effort is futile--I for one, never watched Discovery Home and probably will never watch Planet Green either.