Even if the Heat don't get LeBron, I think they do get Joe Johnson or Amare Stoudemire to go with Dwyane Wade. Those guys can score, so Varnado can focus on what he does best - defend and rebound. I think he needs to develop that jumper on offense, simply because he'll get some open looks if he's playing with those superstars. They won't be throwing the ball to him in the post.
Plus, with the Heat cleaning house for cap space, they'll carry several minimum contracts on the bench. Hopefully Varnado gets one of those. Being a tweener may actually help, if he can be a decent backup at two positions - C and PF.