From MY experience, major updates slow the iPhone and iPod touch down. The Original iPhone and touch were fine on 1.x and a tad slower on 2.x an unbearabley slow on 3.x. The iPhone 3G and 2n generation touch were fine on 2.x, and slightly slower on 3.x and maybe will get even slower on 4.x. So with this pattern, the 3GS and touch 3rd gen will be slower on 4.x. Perhaps so will the iPad. And they don't want that to happen right away, so they delay the update for it. A just release device getting slower in less than 6 months after release is sad, so apple will delay it. That's a guess.
A more releastic guess, and the one I'm more sure about is this.
They released iPad an 3.2. Now it's time to focus on iPhone. So they are working on 4.x for iPhone and iPod touch. And are slowly workin on 4.x fr iPad. Also they are probably hard at work on the 4th generation iPhone. And te iPad has a larger screen, so they will have to take advanage of it. That will take time to get it to look well planned.
Just my guess.
PS: this way typed on an iPhone 3GS... Please excuse me from spelling mistakes.
A more releastic guess, and the one I'm more sure about is this.
They released iPad an 3.2. Now it's time to focus on iPhone. So they are working on 4.x for iPhone and iPod touch. And are slowly workin on 4.x fr iPad. Also they are probably hard at work on the 4th generation iPhone. And te iPad has a larger screen, so they will have to take advanage of it. That will take time to get it to look well planned.
Just my guess.
PS: this way typed on an iPhone 3GS... Please excuse me from spelling mistakes.