Well! It is not something that you will find many people in the US cooking as a dish at home. But, on the other hand, no decent Irish or English pub in the US would dare to not have it on their Menu, along with Shepherd's Pie, Fish and Chips, and Bangers and Mash, etc. Is it good? It does have a unique flavor, and nothing I have eaten in the US, in my travels, is as good as what you get in England. Still, It is a taste that is a little shocking to American palates.
Nope, never seen it here -- but then, so many people I know have been freaked out by Rocky Mountain oysters and stop eating them once they know what they are (hint: not seafood), that I suspect something made out of pig's blood would turn off the vast majority of people here.