I liked the switch. LOST often shows people we don't know or people showing up in places we don't expect without explaining their motivations, and then future flashbacks explain it. I think if they had done it the opposite way around the whole time they were trying to get them on the plane we would be like "oh, they got on the island" and "I wish I knew what was happening with Locke on the island"--and we would already know about Locke's resurrection, which is a huge deal. It's more suspenseful to not know what will happen upon island return, in my opinion. I do see they could have aired them either way, though.
I'm sure they would have re-edited it so we didn't see what he was writing in the note, if they had it the other way around.
But I think it would have been really cool if we had met Illiana and Ceasar first in this episode, and then saw Iliana escorting Sayid in the next one. And Ceasar offering his condolences in the airport. That would have been pretty awesome.
From the official podcast, Carlton and Damon wrote both episodes and pretty much at the same time, and when they looked back on it, they thought 316 would be a bit cooler to show first. I think now that we have seen it, it does make a bit more sense.
Im mixed on this. A lot of stuff woulda been neater to have Life/Death first. For instance, that opening scene woulda been mind blowing: "Wait, theres a plane? What time is this? Who? What?" and then everything woulda fallen into place with 316. HOWEVER, the suicide note was MUCH more powerful reading it first in 316 before seeing Locke's story (which was a bit anticlimactic in my opinion)
For me, it wouldn't have made a damn bit of difference. In fact, I think that seeing this epi second makes more sense. The problem is still with 316... it had far too many things happen that didn't have explanation but that begged for explanation. "The Life and Death of Jeremy Bentham" didn't resolve those issues, IMO. But this episode was fantastic.