Hard as it may be to imagine, not everyone needs multitasking on an iPad, and if you don't need multitasking, then folders would be the most significant new feature on 4.2.
For me, the only times I want multitasking on the iPad is when an app is doing something like downloading files or otherwise updating itself and I get bored and want to do something else while I wait. I also have a few audio apps I sometimes like to run in the background, and a few alarm apps, but the thing is, the times I use them are few and far between. So I can very well imagine that some people would simply never need multitasking -- in fact, I know a few people like that. They only use their iPad to read books/internet and check email. So no, they probably wouldn't even notice that iOS 4 has multitasking.