It is interesting that Arsenal is favoring here. Maybe the only advantage for Arsenal is home ground, nothing else. First of all, both teams are equal on the table with 35 points. What is more interesting, Aston Villa already played with other Top 4 teams. They won against Liverpool (1:3) at Anfield, they won against Manchester United (0:1) at Old Traford and they won against Chelsea (2:1) at Villa Park. If they win against Arsenal, Aston Villa will be the second team doing that after Leeds United in 1994-95. 

Aston Villa is almost complete. Only Emile Heskey is injured , but he is not starter anyway as Norwegian striker John Carew is Martin O’Neill first choice. On other side Arsenal will be without injured Nicklas Bendtner, Gael Clichy, Johan Djourou, Kieran Gibbs, Robin Van Persie and Thomas Rosicky. Cesc Fabregas and Armand Traore are doubtfull.

Aston Villa is in excellent form as they won five out of five last games. Here are the results:

19 Dec (Premier League) Aston Villa - Stoke City 1-0
15 Dec (Premier League) Sunderland – Aston Villa 0-2
12 Dec (Premier League) Man Utd – Aston Villa 0-1
05 Dec (Premier League) Aston Villa - Hull City 3-0
01 Dec (Carling Cup) Portsmouth – Aston Villa 2-4

And finally, Arsenal has no victory in last three years when playing against Aston Villa at home:

2008/09 Arsenal - Aston Villa 0:2

2007/08 Arsenal - Aston Villa 1:1

2006/07 Arsenal - Aston Villa 1:1

I believe Aston Villa is able to make another surprise.If it is a surprise.