From what i've read it's been proven that there is no offloading of processing to the servers, it's all done locally.
EA may claim that, but in fact you can unplug your internet connection once playing and it won't realise that there is no connection for a while surely proves that it merely "checks in" every now and again with the servers and boots you out when it can't?
That was also confirmed by an anonymous developer, that there was no reason, in his opinion, that they shouldn't be able to easily make an offline version without all the extra features that being connected brings.
I've not played it, but have been watching closely as i bought it for the missus in the hope of getting more gaming time myself.