contacts should be synced with an application on your computer which you can then sync with the iPhone. As far as emails and sms those dont just transfer over.. you have to set up an email on your device and whats on the server will download to the phone. you wont be able to transfer text messages though
I was going to say assuming you're using a Mac you could use BB Desktop Manager to sync your contacts into Address Book. However if you're picking up your phone from a service provider they can sync your contacts too.
you have gmail? download google sync to your blackberry. transfer contacts. then on your iphone add the gmail to your iphone native email app...your contacts will be there instantly.