A couple thoughts without much basis.
First, Iginla was way too much. Morrow seems like the key piece to any deal, and if he wasn't enough (with another 1st, for instance), Shero went after Morrow.
Second, Morrow plugs in beautifully on the third line if Malkin comes back soon. Bennet doesn't work there at all, IMO, and Morrow seems a bit slow for Geno/Neal. Sutter has shown he can score when he's with talented players, and Morrow can grind well enough for a third line role. This makes our third line of Sutter/Morrow/Cooke very formidable. TK, Jeffrey, Vitale, Adams, and Glass will rotate in the 4th line. TK will probable be HSed a lot since he can't kill penalties.
Third, win now. Morrow is a lot, but we thought the same about Hossa when we lost Esposito and a 1st. At bottom, Morrow is a low first round pick. If this trade gets us to the SCF, it is well worth it. Holding on to assets so you're consistently among the best in the league is pointless if you don't win Cups.