Kevin Blackwell's Luton Town have made some useful signings, including veteran strikers Paul Furlong and Paul Peschisolido.
Nottingham Forest look good for automatic promotion, having recruited former Celtic skipper Neil Lennon and spent around £1.5m on Yeovil midfielders Arron Davies and Chris Cohen, plus defenders Kevin Wilson and Matt Lockwood.
Swansea, who have sold star striker Lee Trundle to Bristol City but allowed boss Roberto Martinez to sign reinforcements, including Guillem Bauza Mayol, a striker from Espanyol, and the highly rated Liverpool reserve winger Paul Anderson.
Southend have lost Freddy Eastwood but signed another prolific non-League goalscorer in Charlie MacDonald.
Doncaster Rovers, whose signings include former Bournemouth striker James Hayter for a club-record £200k and Oldham's highly rated midfielder Richie Wellens, could be the surprise contenders.