I'd like to know about things in advance. It would be nice if significant changes/issues could be announced via Twitter for those of us who use it. I suppose a Facebook page might work as well, though I suspect the overlap between Stack Overflow/Twitter is probably greater. No reason you couldn't do both and have the tweets automatically published to the Facebook page. Tweets could link to relevant discussions on Meta and/or the blog for more information.
I think this would go a long way in solving some communication issues both in disseminating and finding information about what changes are being made.