I do currently carry both. I have the iPhone for my personal phone, and a BB 8700 for my work device. I really like the iPhone for the same obvious reasons as most people do, and as I'm sure you will having had the iPod Touch. The iPod is great to always have on you, especially if you can use your Apple headset for making and receiving phone calls while you listen to the iPod. The online browsing is fantastic. I actually prefer to text from my BB as opposed to the iPhone, but what can you do?
With all that being said, I do plan on switching from my iPhone to the BB Bold when it comes out this summer. Just don't tell my wife that