I hope it comes to UK users soon.
I hope that by the time we get it here the bugs have been worked out. Such as the fact that it seems that, unless the card is still showing in the app from when you asked it to remember something, there is no way to ask it to forget it. This means that you can have something like this happen:
You: Alexa, remember the keys are in the drawer
Alexa: I'll remember that for you
...some time later...
You: Alexa, remember the keys are on the table
Alexa: I'll remember that for you
...some time later...
You: Alexa, Where are the keys?
Alexa: The keys are in the drawer. The keys are on the table.