You want a #6?
Nuff said
I can't believe I agree. Hughes is a better candidate right now than any of the other middle order guys knocking on the door. The only reason I can think of that he can't play well at #6 is that he's not used to it.
For what it's worth, here's how I'd rate potential replacements right now:
1. Phil Hughes
2. Cameron White - he's not obviously better with bat than most of these guys, but gets extra points for ODI form, leadership potential, slip catching and ability to bowl a bit. Note I'm not particularly a White-fanboy, it's just the selectors will always go for these things in a tight race for a spot
3. Chris Rogers - Ponting/squad don't like him it's rumoured, so he mightn't be a chance
4. Dave Hussey - as Robelinda points out, has technical worries to down play his run scoring record. Age doesn't really help Dave or Rogers either.
5. Brad Hodge - too old to get picked for an unimportant series and now that he's retiring - forget it.
6. Mark Cosgrove - would be a good #6 I reckon
7. Michael Klinger
8. Usman Khawaja - NSW bias might get him in quicker

9. George Bailey
10. Shaun Marsh
Others: Adam Voges, Phil Jaques, Steve Smith.
How those guys fit into the order is a whole different story. Watson probably stays up top for now. Does Katich move? He looks too dodgy against spin to me to get put down lower. The more I think about it, the more I like Hughes at #6.