The thing is, Hilf won't play and Casson's only hope is if the selectors take a fancy to a flat or dusty surface. If a bowler goes down, their first choice will be Noffke. With both Bollinger and Siddle looking at post-season layoffs, there would seem to be little choice but to continue to work with Hilfenhaus. The Windies would have to double their recent performances to make Australia sweat about playing 4 pacemen and many would suggest the attack would improve if Johnson was absent. I'm sure they would have picked McGain if they couldn't use MacGill, but they've got him. There's little point taking a 35 year old for the sake of development and experience.
In the ODI side, I think they've picked well apart from the glaring lack of spin. Well, actually there are 4 players who could quite reasonably be expected to bowl spin, but no specialist.
It's smart to pick a top-order batsman among your reserves, especially with few one-day openers to look at and concerns over fatigue to Test players. Marsh was highly consistent this past season and maybe even the most improved player in the competition. Pomersbach, apart from not being an opener, does not know his one-day game yet. Does his List A record warrant ODI selection? To pick him on talent alone is to deny that Marsh is himself a very classy stroke maker who also has been able to convert some of that potential into runs. I'd also expect Travis Birt and Phil Hughes took substantial consideration.