For what it's worth, here's my basic run-down on some of the more obvious candidates:

Openers:

Compton: clear frontrunner, division one performances speak for themselves
Newman: perhaps uninspiring but not facing much of a challenge

Middle Order:

Joyce: next in line for the Test side
Yardy: great season, decent prospect but not talked up as Pietersen / Bell were
Shah / Sales: perhaps the best of an indifferent and uninspiring lot, not setting the world alight

Bits-n-pieces options:

Clarke: great season batting without convincing doubters, bowling going backwards
Dalrymple: great temperament, great start in ODIs, possibly a long term no 6/7 Test bat and second spinner
Mascarenhas: awesome bowling season without convincing doubters, batting nothing special

Wicketkeepers:

Foster: should perhaps have been in the test side throughout the last few years
Davies: brightest wicket-keeping prospect around, very promising batsman

Spinners:

Rashid: young, raw, has potential with ball and can bat
Doshi: the finished article, solid rather than spectacular

Seamers:

Tremlett: was ahead of Mahmood and Plunkett before his injury, decent prospect
Mahmood: encouraging signs amid the dross, finished recent ODI series encouragingly
Broad: bright prospect, can do a bit with the ball but raw
Smith: perhaps the brightest bowling prospect of the upcoming crop
Onions: clearly being looked at, very raw