That's incorrect. All mobile Core i5 processors have HyperThreading.

http://ark.intel.com/ProductCollection.aspx?familyID=43483

In fact, there are only two Core i* processors that don't have HyperThreading support, and they're both variants of the same quad-core Core i5 desktop processor (Core i5 750 and Core i5 750S):

http://ark.intel.com/ProductCollection.aspx?familyID=42912