Ancestry.com now has an index with images for many Canadian Passenger lists 1865 - 1935. Look for a link on the Ancestry.com or Ancestry.ca home page as this index doesn't seem to be in the 'card catalog' yet.
All these same passenger list images are available free at Library and Archives Canada's website. There is no name index there, however, many of these entries, particularly those through the U.K. and Scandinavia, are already available through outbound indexes and some free Canadian inbound indexes. I hope that the drive to continue free indexing to these Canadian genealogical resources isn't lessened in any way.
**Dave Obee has reminded me that the Canadian lists for 1925-1935 are NOT digitized and available on the LAC site, although they are available now on Ancestry.com. I simplified things way too far. Do check the LAC section link below for information on what's available at LAC's website and on microfilm from LAC. **
This Ancestry index does not yet include the 'Form A' arrivals - between 1919-1924. Families and other groups of passengers are not linked. There are links to images of the ships though most of those are available on-line elsewhere.
For an explanation of the various passenger and immigration forms and lists, see Library and Archives Canada's Canadian Genealogy Centre's 'Immigration and Citizenship' section: http://www.collectionscanada.gc.ca/genealogy/022-908-e.html
For the Scandinavians, I see the spelling is retained, if used on the record, but this doesn't seem to carry over into the index search - e.g. Löfholm, Lofholm
I've already made a couple of corrections to Ancestry's indexing and I can see that there are 100's or more in this index without surnames or without either first or surnames. In some cases this will be due to the appallingly poor microfilms we have of these records, most of which were later destroyed. In some cases, of course, it might be due to insufficient time or knowledge invested in the indexing.
Ancestry.com, a commercial company, was apparently given permission to house copies of these passenger lists on its site. We Canadians should be able to see the details of the agreement Library and Archives Canada made with The Generations Network (Ancestry.com).