I answered that question in the other thread ... here was my quick answer:
Here are a few uses that I came up with in 60 seconds:
1.) Gain reach.
2.) Gain improved grab/constrict/etc ... and other special attacks.
3.) Disguise oneself.
4.) Increase movement for short durations.
5.) Flight.
6.) Underwater action.
7.) Gain traits of the form such as low-light vision (animals) or immunity to poison (plants) [Note - this issue is still not 100% clear, but the designer, Andy Collins, is on the record as saying that you gain extraordinary type traits of the form via polymorph]
8.) Healing (my sorcerer certainly enjoys this aspect).
9.) Increasing strength without using an enhancement bonus.
I will point out that adding to your base strength via polymorph is one of the most broken things in the game. A character that begins the game with a 20 strength and increases it 4 times by 16th level has a 24 strength. If he polymorphs into a fire giant, he gets 7 more points of strength. That is a heck of a bonus to combat ability. For your average wizard, being able to change into a fire giant means being able to do serious damage in combat.
Will he be able to stand in combat and deal damage round after round? Not without other spells to boost his hit points or AC up significantly, but this spell has far more uses than just the hit point bank many PCs saw it as.
