Well lets say it's like this:
Pot 1: Barcelona, Chelsea, Livepool, ManUtd, Milan, Arsenal, Sevilla, Bayern
Pot 2: Lyon, Inter, Real Madrid, CSKA Moscow, AZ Alkmaar, Juventus, Rangers
Pot 3: Olympiakos, Marseille, Dinamo Kiev, Stuttgart, Fiorentina, Atletico, Bordeaux, Besiktas
Pot 4: København, Levski, Wolfsburg, Standard, Maccabi Haifa, Zürich, Rubin Kazan, Unirea.
We can't get team from pot 2, we can't get an Italian team from the other pots and we can't get 2 teams from the same country.
The toughest group will be:
1. Chelsea/Manchester
2. Juventus
3. Atletico Madrid
4. Wolfsburg
The easiest:
1. Sevilla
2. Juventus
3. Besiktas
4. Unirea/ Zurich/ Levski
Medium:
1. Arsenal
2. Juventus
3. Stuttgart
4. Standard