2 iPad1,1
    1 iPad2,1
    1 iPad2,3

    3 iPhone1,1
    2 iPhone1,2
    2 iPhone2,1
    1 iPhone3,1
    1 iPhone3,3

    2 iPod2,1
    1 iPod3,1
    2 iPod4,1

    4 AppleTV2,1

    + tons of Android devices

Really, you need a lot of devices as a developer if you are going to seriously test anything, given the number of firmware/device pairings seen in the wild, especially given that Apple actually refuses to allow developers to manually reflash their phones with non-current firmware versions. :(