It's apparently not a Zavvi exclusive, as it's on Arrow's site as well. I received the notice from Zavvi - I surmise it might also be at TH(amilton Books)E (Best B) U(y)SUA(mazon)(Barnes & Nob)L(E) S(Deep DiscoU(nt)SPECT(arget)S ... etc. Assuming it isn't a UK exclusive...
Zavvi/Arrow will be releasing 4K versions of Silent Running starring Bruce Dern. Directed by Douglas Trumbull.
Featuring a deluxe steelbook edition
...And two non-bunch of Huey (Dewey & Louie) editions ...*
*H,D & L are still in the film ...