It's early yet, but here's my best prediction for Miami's opening night lineup:
C Udonis Haslem
He's not going to be able to live here, but Haslem is too good to leave out of the starting five. Others may play more minutes at the position as Haslem gets his run at power forward, but Haslem's post defense, rebounding, reliable jumper and all-around pedigree earn him the nod.
PF Michael Beasley
There's going to be a lot of overlap between the two forward positions, but I think Beasley's future is at the four. His post arsenal and rebounding demand that he spend a good chunk of his minutes in and around the paint, even if his perimeter game and post defense suggest the opposite.
SF Shawn Marion
Who knows who Marion will end up guarding - probably everyone from LeBron James to Chris Bosh - but he's a natural 3 to me. A power forward in Phoenix is not a power forward in Miami (or wasn't until the Phoenix turned into Miami). He's an upwardly mobile wing. Unless/until he gets traded.
SG Dwyane Wade
He excelled in a sixth man role in Beijing, but I think he'll crack the five in Miami.
PG Marcus Banks
I'm betting against Chris Quinn because of the way he looks (suspicions confirmed, Quinny!) Seriously, I think Banks is going to figure it out this year, and his speed makes him an ideal fit for this lineup. I like Quinn as the anchor of the second team, and Banks running with the top five.