The Lakers cannot sweep Detroit or Boston. Period. But, IMO, Boston will not beat the Lakers in a 7 game series, if they meet. Denver > Atlanta, and Utah > Cleveland, and, based on the competition IN THESE PLAYOFFS, the Lakers seem to have come together and are poised to make a serious run. Boston, on the other hand, are very inconsistant, and...I wouldn't say they don't have heart, but they don't have the mental toughness, if that makes sense.
I'd take L.A. over Boston...and Detroit vs L.A. would be more competitive, I think.