You are going to need a data plan for the Blackberry and such, but the SIM should work. Also as someone with a Blackberry I feel you should be warned that the apps suck and aren't going to improve at the rate their company is tanking. E-mail works perfect, but everything else provided by 3rd parties is an afterthought. I uninstalled my Facebook and Twitter apps and just use the mobile web versions. Yelp just plain does not work. Games are non-existent.
And this is coming from someone who likes their Blackberry still. My contract only has a few months to go and at this point I am usually ready to throw my phone in the ocean, but not with this phone. Plus once I switch to the iPhone I have to start worrying when I drop my phone again, having my battery not even last a whole day, and constantly hitting the wrong letter when typing.