I'm in the minority as usual, but I don't see any point in the Suns re-signing McDyess.
Say they sign him to a two-year contract. What is he going to do for them? Lead them to a championship? Of course not. He'll be worth a few wins, and the cost will be that he'll take the role that the Suns originally earmarked for Zarko (remember 'tall ball'?), meaning that Zarko will wind up spending most of his three-year rookie contract on the bench.
It's probably a moot point, though, because I bet McDyess would prefer to go where he knows he'll get playing time, instead of staying here and hoping against the best-case scenario, where both Lampe and Zarko get good over the summer. If money is an issue (and it probably is) then McDyess is going to wind up with a team that needs to win now; that's the only way a team will throw a decent-sized long-term contract at an injury-prone, aging big man.
My bet is that McDyess either winds up finishing his circle of contrition in New Jersey, or goes back to Denver to replace Chris Anderson as the Nuggets' third big...until they trade him again, at least...