As far as I'm concerned... pre- 6N, these positions are concrete, barring major incident:
1.
2.
3. Murray
4.
5. O'Connell
6.
7.
8.
9. Blair
10.
11. Williams
12.
13.
14.
15. Byrne
really and truly, no one else has really put their name down and said 'you wouldn't dream of not picking me'.
For the other prop berth, it has to be between Sheridan and Jenkins, but AS certainly hasn't done much lately so Jenkins is in pole, but it's far from decided.
Any one of 6-8 hookers could play, none are outstanding.
The other lock would be difficult too because there's Wyn-Jones, O'Callaghan and Hines all playing very well atm.
Back row has Powell, Williams and Wallace at the forefront, but there are plenty of other players from all four nations who could do the job nicely; it's not an area the British Isles is short in.
10 is a big problem, because you can go for solid and boring Jones or flashy and chokey O'Gara. There's no one in Scotland, and Hook/ Cipriani are both massive liabilities.
The centres, on ability, would be Henson and BOD. But Henson hasn't done anything for a year, and needs to prove himself this 6N. I keep saying this, BOD looks slow and past it atm, so 13 is wide open... Henson should play 12 if he's fit.
THe other wing could be one of about 10 players... none of whom are shoe-ins for their own international teams... there's Halfpenny, Kearney, Fitzgerald, Earls, Evans, Lamont(s), Sackey and several other English wingers who are all definitely excellent players, all exciting, but all flawed, even if that flaw is only inexperience.
For all these positions, we'll have to see from the 6N who should fill them.