It looks like that you are leaning more to keeping your iPod. Since you mentioned Env2, I'm guessing you are on Verizon - so why not get an iPhone now? I mean, sure it won't be the latest iPhone in a few months but I still think its better than going completely Android if that means you need to give up your iPod Touch anyways. An iPhone is basically an iPod Touch that can call, make texts, and connect to the internet anywhere without using WiFi.
As for convincing them to let you keep it, you should just explain to them that you really like iOS and you don't want to give it up for Android because it's sycns with iTunes, all the apps you invested would be gone, etc.
Honestly, I'd get an iPhone.