I actually think Leinster has a fairly good chance to qualify, pool 6 being the only pool where the second ranked team (Leinster) won't play against the first ranked team.
Clermont, Toulon, Harlequins are qualified unless you believe in miracles.
In pool 1, Saracens should win in paris and qualify, Munster can reach 20/21 points.
Pool 2 is incredibly competitive. Admitting Toulouse will get the bonus point at home against Treviso, the Osprey-Leicester game will be decisive as well as the Leicester Toulouse game. Bonus points will be critical but it is unlikely that the best second will come from this pool unless we see a try feast in the remaining games.
In pool 3, Harlequins to qualify but the best second will not come from this pool.
Pool 4, Ulster should top the pool, the best second will have less than 20 points.
Pool 5 ,Clermont to top the pool with 23+ points and Leinster second with 20 points, they must however improve their try soring record which has been very poor so far this season (3 in 4 games).
I sniff controversy at the last game of pool 6, Montpellier-Toulon, as Toulon, if already qualified, could field a second string team, opening the door for Montpellier to snatch a second best spot. Montpellier to finish then with 21/22 points provided they beat Sale away from home.
So my predictions:
Pool winners: Harlequins, Clermont, Toulon, Ulster, Saracens, Toulouse or Leicester
Best Second: Two among Montpellier, Munster, Leinster
So for the QF, we should see:
2 or 3 teams from premiership
1 to 3 teams, but most likely 2, from rabo 12, all of them Irish
2 to 4 teams from Top 14.