Don't ever count them out - they will never give up - even if the Brady Campaign or Soros or Bloomberg or Peters gave up or quit - there will always be the next individual or group ready to step up to the plate - in a way it is not even so much just guns as it is control. There are always people who think they know what is best for everyone and they are always willing to try to use organized and institutional force to make everyone else do what they believe is right or for the ultimate good.
In fact many individuals who are pro-liberty when it comes to the RKBA are pro-control when it comes to many other issues. There is a good quote by Tolkien's friend C.S. Lewis:
"Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience."
So, the forces of gun control will wax and wane - but they will never cease - remember Heller was 5 to 4 - one liberal in place of 73 or 74 year old Scalia or Kennedy and it would suddenly be a different judicial world for the second amendment and therefore for all sorts of possible new gun control legislation or executive orders.
We haven't won much of anything yet in the grand scheme of things - we won a huge victory in Heller and hopefully McDonald next, but the battle to define the scope of the second amendment is just begun and our liberties are in many ways still more constricted than past generations.
The gun controllers aren't dumb - they know they have lost Heller and McDonald so they are already on to the next battle - laying the public propaganda to justify restricting the scope of the second and waiting for a liberal court to start doing so. Even if they can't get Heller or McDonald (if it goes our way) reversed (and with enough of a liberal majority on the court they might) they can still effectively gut the RKBA through the reasonable restrictions of a liberal court defining and limiting the scope of the RKBA.