No, you don't have to leave Canada to "land" anymore - they brought in new legislation
You do have to have valid temporary status though.
http://www.cic.gc.ca/english/resources/manuals/bulletins/2008/ob076.asp
With the introduction of the Canadian Experience Class (CEC), launched on September 17, 2008, amendments were made to the Immigration and Refugee Protection Regulations to allow foreign nationals with valid temporary resident status in Canada to be granted permanent residence from within Canada. The changes make it easier for these temporary residents to acquire permanent residence since they no longer need to do so at a port of entry (POE). These regulatory changes apply to all foreign nationals in the Economic and Family classes who have valid temporary resident status in Canada.
You will receive a letter when PR is granted to tell you the following:
Please note that if you are already in Canada and have valid temporary resident status, you now have the option of obtaining your permanent resident status in Canada as opposed to leaving Canada and re-entering at a port of entry. Please contact CIC’s Call Centre at 1-888-242-2100 as soon as possible to arrange an appointment with the nearest Citizenship and Immigration office to your place of residence. (You cannot call this number if you are outside Canada.)
