I completely agree Al. For a *relatively* simple matter like this (reciprocal rights of UK citizens in the EU to stay where they are, and for EU citizens in the UK to stay where they are), but for something so crucial to so many families and businesses, it's mad not to have a gentleman's agreement already in place between the UK govt and the EU.
I don't think allowing EU nationals already in the UK to stay indefinitely, will make a material difference to problems like housing, NHS, schools etc. It will help to give families stability (if you're Polish and you're about to choose a school for your child, what do you do? Gamble on being allowed to stay in the UK? Jack in your job and home and move back to the EU?) , and ensure business continuity (if you're a restaurant and you employ a lot of EU nationals, how worried would you be?)
Hopefully mwilkinson is right here - I suspect I would have heard about it if the EU ruled it out.