The Canada Border Services Agency has published a Fact Sheet entitled "The Canada Border Services Agency's Implementation of the Ontario and British Columbia Harmonized Sales Tax" (June 2010), which sets out some of information importers should know about HST.
In short, HST will be applied in respect of non-commercial goods (a.k.a things individuals import for personal use). The "official definition of a "non-commercial good" is: "Non-commercial goods" means "all goods, other than goods imported into Canada for sale, or for any commercial, industrial, occupational, institutional, or other like use."
Beginning July 1, 2010, the importation into Canada of non-commercial goods by or for a consumer that is a resident of Ontario or British Columbia, will be subject to the HST. The HST will apply to non-commercial goods destined for Ontario and British Columbia, regardless of where the goods enter into Canada. NOTE: Goods destined for Nova Scotia, New Brunswick, and Newfoundland/Labrador are also subject to HST.
MORE IMPORTANTLY - As is the case today, the provincial component of the HST will not generally apply to commercial goods that are imported by an HST registrant for consumption, use or supply exclusively in the course of the commercial activities of the registrant.
For more information, please see the Fact Sheet.