It seems unlikely that the 2sec delay will be fixed, at least on iPad 2. The reason being that it takes some time to load the app's frozen state.
The swipe gesture let's you move to another app directly, meaning you see it's interface when the app itself hasn't even finished loading. But when using the multitaskbar, it first shows an animation of the app moving into the foreground.
The reason I am mentioning this is, to note that the multitaskbar is not a faster way of switching between apps, it only feels faster, because the brain gets temporarily distracted by the app opening animation.