the suns don't necessarily need shaq, but his presence will help slow down tim duncan, which is basically all the suns wanted. imagine if shaq actually dropped the weight, he could really be dangerous. he'll probably have to since the suns run all over the floor. i think the acquisition was good, but the suns have to limit his minutes; they don't need to justify the trade by playing him a lot...that won't work for anyone right out of the gate.
the cavaliers probably gave up a little too much. larry hughes and drew gooden are better players than wally and wallace. but it doesn't really matter since the trade was basically made to make lebron james happy, which it did.