See my post 89. The issue to be reviewed is VERY narrow, not wide. The Court will only decide the collective/individual issue regarding guns for use in the home in Washington DC.
BTW, how do you know that both sides wanted it? I haven't been able to find any tally of votes for certiorari on this one.
DC lost in Federal court and on appeal, and demonstrated their desire for the Supremes to reverse in a petition for certoriari. The lower court victors in Parker vs. DC filed a “cross-petition for certoriari” which means they too wanted a ruling from our nine unelected black robed masters.
http://www.gurapossessky.com/news/parker/documents/heller_cert_petition.pdf
By both sides I meant those prosecuting it and those defending it. Not the justices - I have no idea of which justices granted a review.