It is highly possible this is a "testing the water" scenario. If Henry floats, they might move more production units over here. If Henry sinks, you might see just this batch and no more. However, saying that, Henry is expanding their factory grounds already anyway to make the Henry Quick and maybe they might be able to ramp up production to make orders for US market.
USA has a TON of tub-style vacuums and to us here, we associate them with Shop-Vacs and stuff for cleaning up industrial waste. Not something for the house - not in the living room anyway. And that $600 price tag they are getting on HSN will completely obliterate them from the working environment. Will take some convincing to get these to shift in America. Most people will be like "I have a shop vac why would i need this?"
I suspect just like in the UK, they will be highly popular in houses with children, so that will be your strong market leader. Maybe schools or daycares might grab one?
Will be interesting to see how it goes, to me it seems kind of unusual to see a Henry vac not in England - it seems like that's a piece of Britain that belongs at home.