You'll be finding less and less places/people online who won't be charging you the full HST anymore. Most people just haven't been bothering to comply, but I guess the Atlantic Provinces have been flexing their muscle or something.
http://www.ctf.ca/articles/News.asp?article_ID=162
"At first, the planned harmonization seemed only to affect businesses operating in the three harmonized Atlantic provinces, but it is now clear that any business is affected if it makes supplies to recipients in these provinces or acquires goods and services from vendors there. It is irrelevant where a business resides; the place where the goods or services are supplied or deemed to be supplied dictates the applicable tax rate. The place of supply rules are the crux of the HST and determine whether HST must be collected on any given transaction. HST must be collected on most taxable supplies into participating provinces even if a supplier has no presence there, a notable departure from longstanding PST practice. The rules for goods are fairly straightforward. Goods are considered to be sold where they are delivered or made available. If a vendor delivers tangible personal property to a participating province either directly or via a common carrier, it is subject to 15 percent HST. Special rules apply to rentals and leases."