We've got a number of requests for things that folks would like to see on the home screen; the things that are there now are the things that we figure almost everyone would use. Next Actions are somewhat of a GTD-ism; if you use some other productivity method, you may not use them or know what they are. For that type of user, a top-level item would represent wasted screen real estate at best, and a source of "this app is too complicated" feelings at worst. Software engineering is all about tradeoffs...
In any case, in some future version of the app, we may add more items to the home screen, or make it customizable; folks that would like to see stuff added there should send email to the support ninjas so we can record that feedback.
>>>>>>> "make it cutomizable;" <<<<<<<<<<
This is critical for a device with such limited real estate!!!! You always going to be wasting someone's (possibly everyone's) OF iPhone real estate when you try to choose what's on the home screen for us.
Obviously within reason, but isn't that in a sense what you are doing with Perspectives on the Desktop OF when user created Perspectives appear as options in the customizable toolbar window? If you slightly less ambitious you could solicit from users votes for the top 30 perspectives. and with discussion may you might find some surprises and in Settings allow us to choose what we put on the home screen rather than your suggested default.