Well first, there is no shortage of public parks in Denver and if you head out to Jeffco there is a massive amount of open space.  With that said, there is no reason to believe that allowing more building up will open any more open space.  The city and county of Denver is built out and other than the plan to move I70 below grade there isn't going to be any added open space.  The trick will be to keep the developers from finding ways to abscond with any of our existing parks and open spaces.  One idea may be to look at some of Denver's municipal golf courses and see if they should be re-purposed to better use by the residents.