All eyes will be on Manchester City as the window opens. Roberto Mancini is expected to add more firepower to a squad who have emerged as genuine contenders for the Premier League title.
The main targets
Wolfsburg striker Edin Dzeko is top of their shopping list, with Emmanuel Adebayor and Roque Santa Cruz likely to depart, probably on loan.
Arsenal manager Arsene Wenger and Man United's Alex Ferguson are not keen on signing in January, but Chelsea and Tottenham could be active.
For the champions
Carlo Ancelotti will be in the market for flair and goals, although any attempt to sign Tottenham's Luca Modric would be strongly resisted.
Also, Liverpool's new owners will be under pressure to spend as the side slide.
Real Madrid coach Jose Mourinho has made it clear he would like another striker as cover for Argentina forward Gonzalo Higuain, whose back injury may require surgery and could sideline him for a couple of months. But club officials have been guarded about the idea and Mourinho could deploy Cristiano Ronaldo at centre forward, with fit-again Brazil playmaker Kaka playing behind and Mesut Ozil and Angel Di Maria providing width and creativity on flanks.
Big name transfer
Champions Barcelona strengthened their squad by landing Netherlands and Eindhoven's attacking midfielder Ibrahim Afellay, and sporting director Andoni Zubizarreta said the league leaders are not planning any more purchases in January.
In an otherwise quiet transfer market, Atletico Madrid completed the purchase of Brazil midfielder Elias and loaned goalkeeper Sergio Asenjo and sold midfielder Ignacio Camacho to struggling Malaga.
Stuttgart are expected to be active in the market as they attempt to climb out of the relegation zone. Japanese forward Shinji Okazaki has been named as their main target.
Bayern are not expected to go wild, with striker Mario Gomez having found his scoring touch, Franck Ribery coming back from injury and Arjen Robben also set to return to the side.
There is speculation linking them with Swiss teenage winger Xherdan Shaquiri, though he is likely to be an investment for the future.
The champions are also reported to be chasing Hoffenheim's Brazilian midfielder Luiz Gustavo, another indication that Mark van Bommel's days at the club could be numbered.
Schalke, who signed Real Madrid striker Raul during the summer, are now reported to be chasing defender Ezequiel Garay from the same club.
Ronaldinho looks set to be the biggest departure from Serie A with his former Brazilian club Gremio keen to take him from AC Milan. The former world player of the year, whose form has declined rapidly in the past five seasons, has mainly been used as a substitute under new coach Massimiliano Allegri and, with his Milan contract up in June, the league leaders may cash in.
Big name transfer
Italy forward Antonio Cassano will sign for Milan from Sampdoria. A long-term injury to Filippo Inzaghi and fitness worries over Alexandre Pato mean Milan may want another striker. But Genoa have denied contact over Luca Toni.
Juventus are searching for a striker with Fiorentina's Alberto Gilardino the latest to be linked to the Turin club in the media while Lazio are interested in Manchester City's forgotten forward Roque Santa Cruz.