Slightly off topic because it isn't about Sam's position in the running order, but about the leaderboard as a whole (but I'm referring to posts that say they think Sam's being favourited).
The way I see it is that they want Johnson gone tonight and the only way that will happen is having Sam top.
Chloe is obviously the most popular since she hasn't hit the bottom two, yet, so I'm pretty confident she will pull through being third on the leaderboard.
I'd also guess Laura's the least favourite of the three better skaters, too, and remember the producers have access to the voting figures, so by putting Sam first and Laura second, it gives Sam a better chance of getting through with Chloe which means they have the three best skaters in the final because they avoid two of the best facing each other.
If they had Laura top and Sam second, we may well have seen a Laura vs. Sam skate off but with the leaderboard how it is, I think it's more than likely it will now be Laura vs. Johnson.