Utd in Pot 3 if they progress through playoff.
Giggle.
Unfortunately not.
The coefficient ranking used for this season has already been determined as the total points accrued in the previous 5 seasons (2014/15, 2013/14, 2012/13, 2011/12 and 2010/11). For United that total is 103.078, for City it's 87.078. However, for next season UEFA ditch the points accrued in 2010/11, and replace them with the points accrued in 2015/16. This happens every year. In 2010/11 City reached the UEFA Cup 3rd round (the one before the Quarter Final) before losing 2-1 on aggregate to Dynamo Kiev, so we lose some, but not a huge amount of points. In 2010/11 United, on the other hand, lost in the Champion's League Final 3-1 to Barcelona, at Wembley so will lose a shit load of points. The points gained in 2015/16 are, as yet, undetermined. City are likely to raise their coefficient above the 87 point mark as we aren't replacing a huge amount of points anyway, United are highly likely to drop significantly down from their 103 points as they aren't likely to reach the final again, and may struggle to progress past Round 2 (given they won't be a Pot 1 side for the first time in, probably, 2 decades).
EDIT: - Having just done the maths, City are "losing" 16.672 points from the 2010/11 season, to be replaced with whatever we accrue in the 2015/16 season. United, however, are "losing" 36.672 from the 2010/2011 season.