Actually a smart move by Miami getting only a 1 year deal. This is basically like Wade not opting out. Kind of sucks for Wade that he couldn't get a multi-year deal. If Miami was really "committed" or thought he was integral to the franchise or something, then you'd give him a multi-year with a player option. This contract basically says, we're not playing for next year, so we'll give you a bunch of money since there isn't anyone else to give it to.
I can see Wade leaving for whatever contender needs a super-sixth man next year. What it does for the Heat is give them flexibility. I hate to say it but they have a pretty good scenario going, the only large contracts are Bosh and Dragic (questionable pieces to build around, but its who was available and better than most of the teams in the league). Wade comes off the books, Winslow is on a rookie contract (how the hell he fell that far is beyond me) and Whiteside will have a minimal cap hold because he doesnt make much. Basically, they should be able to have room for someone for the max and could sell potential FAs on adding to a Whiteside, Bosh, Dragic, and Winslow core, which is a pretty decent position to be in considering that Lebron just up and left them and they are strapped for picks the next few years. The only catch is that I believe Whiteside has no rights so Miami can't offer more than other teams, but I'm not sure on that last one. Oh and Whiteside might turn out to be a total bust, that could happen too, though he looked damn good at the end of last season.