I see it in most online stores (none around me carry it anyway)... I think newragdoll is right - its not here so its not made line. I was told same thing about World's Best today (even though they had the multicat version in stock just not the regular)
maybe they just changed the bottle for the 'just for cats' line. I swear by that stuff (adopted an old rabbit from the aspca who had trouble with her aim in the litter box) and still find the regular bottles in all my local pet stores.
If you read the label closely, it say the lab that makes the formula is now distributing it on their own. Sounds like the contract was up and they realized they could be making more money selling it themselves. Nature's Miracle probably has a certain amount left and once it's gone you won't find it anymore.