Maybe I am wrong and there are visa holders feeling absolute confidence at the moment, but I would like to hear why from even one before considering your "a few people" categorization as anything but spin.
It's so far out of line of reason to believe that the US is going to basically end all - or any meaningful portion of - legal immigration, as to be nearly impossible to reply to. Where to start?
The US will switch, if anything, to a merit based system. Canada already uses just such a system. Nobody seems to be outraged about it, or proclaiming the end of Canada because of it. There's far too much emotion in this thread.
But all Europeans that would like to get visa are on hold right now. People that already have one are in limbo, worrying about how the coming ruling will affect them.