Looking quickly through the claims they don't appear to cover having a circular magnetic connector - instead it's specified (eg in claim 1) that the connector has 2-fold symmetry and in other claims that the 3 connections are arranged linearly.

The other point you might "attack" the claims on (ie in designing around them) appears to be the inclusion of "bias". Mind you it's not entirely clear¹ what is meant (without referring to the description) by "biased" here: claim 6 suggests it means sprung in some way.

Edit: looking at a couple of pieces of the prior art http://www.google.com/patents/us7311526#backward-citations it seems the main innovation in the Apple claims is probably the symmetry / reversible nature of the connector. There were already circular connectors, eg the cited US3808577, so Apple's claims may have had to work around those - hence the construction including the symmetry clauses. Seems a magnetic connector is well doable even without any need for invention, just based on expired patent disclosures.

Apple paid off the deep fat fryer company who owned the original magsafe patent.