Granted, I've never submitted an app to the App store (outside of work) and I do have some serious reservations about how Apple runs the store, but I actually like the fact that the only way to slideload apps on the device is to jailbreak or compile and install the app yourself (provided you sign up as an apple developer account). I think the lack of officially sanctioned slideloading keeps the device simpler, and in my mind that's more secure.