I've not actually found the lack of multitasking to be an issue, because it does multitask enough.

Mail is push, so that downloads in the background. Music / podcasts can be played while other things are going on. Safari keeps track of webpages open as you switch between applications. Copy and Paste works across apps.

I've not hit a situation where I've felt the need to have two apps open as opposed to just reopening the ones that I need. Mileage obviously varies.