Well lets look at the options for Australia for Mike Hussey replacements.
Usman Khawaja (this season: 438 @ 39; career 4045 @ 43)
Solid player but has been found out in his short Test career due his inability to rotate the strike and issues with the swing new ball outside off stump. Has improved some of technique issues in the last two seasons in England and Australia. Though he has been that dominate at domestic level as he was when he first came on the scene. Improved his fielding, but would be liability at 3rd slip. Can bowl some medium pace but it pretty random crap. Will probably get first shot due to ODI players having no FC matches to push for selection.
George Bailey (this season: 169 @ 28, career: 5586 @ 39)
Would be like for like replacement for Hussey. Lower middle order batsmen, captaincy ability and decent gully fielder. Only problem is his lack of runs this season and generally inconsistency throughout his career. He hasn't looked out of place at International level in ODIs and T20Is. For mine needs more runs at FC level, but he may not play another FC game this season.
Callum Ferguson (this season: 463 @ 42, career: 4295 @ 36)
An outside change, but always 'looked' like a Test standard batsmen when he gets going. A good start to the career. If he continue to have a big season, he could be seen as a project player at 6. I don't think he has the application to be Test cricketer, when he gets tough Callum goes missing.
Alex Doolan (this season: 409 @ 58, career: 2311 @ 39)
Having a break out season. But reckon the last thing Australia needs is a flash in pan type player. They would be looking for someone who they can develop into a 5-10 year Test career. Though if keeps scoring runs then the home Ashes series is not out of sight.
Mark Cosgrove (this season: 373 @ 37, career: 7975 @ 43)
The fat bastard has the best technique of the batsmen in contention. But I can't see the selectors getting past his weight. Though he is decent seam bowler and handy slip fielder (well when the ball goes straight to him and he doesn't have to dive).
Joe Burns (this season: 305 @ 30, career: 1480 @ 42)
He done some work on his game to improve his short form game. But I think it has made him go backwards in FC cricket. Having a poor season at FC level. Solid batsmen, but he needs a couple more season of work on his game.
Steve Smith (this season: 224 @ 32, career: 2391 @ 41)
Disgusting technique, but finds a way to score runs. Having an average season, so far, but it might be a blessing in disguise. As he likely to miss ODI selection and can push for selection playing FC cricket. Still viewed as all rounder in the selectors eye (even though he doesn't bowl anymore) and good fielder. So he meets the needs of being a multi dimension cricket. Will be smokey for India as spin bowling all rounder, even if he doesn't ball another ball for NSW this season.
Glen Maxwell (this season 90 @ 22, career: 924 @ 42)
Like a lot of young batsmen has a good technique, but a poor temperament due to influx of limited over cricket. If he can work on his temperament I don't think he would far from selection a lower middle order batsmen that can bowl. The new number 6 for Australia? Having a poor season after getting his first chance up the order for Victoria, is not a good sign. He will go down the same path as White and Smith and will have focus more on his batting to get a regular spot in National teams. But unlike though two doesn't try too many things with the ball, so it won't affect his bowling as much.
There is also some outside chances like Dave Hussey, Chris Rogers, Rob Quiney, Brad Haddin, Cameron White and Micheal Klinger. But I reckon the selectors will be looking for a player that is younger or a specialist lower middle order batsmen.
It is also interesting that an average above 40 is par for International selection. I remember when you had to average above 50 to get a look in to Australian team. The pitches are partly to play, but I think it more of an overall sign of the drop in batting standards.