IMHO, LRM will not achieve status anywhere near Charles Manson. Manson was the head of a cult, a sort of hippie commune that tied some weird importance to The Beatles's song "Helter Skelter". And Manson was also a song writer before he was jailed; he even knew (by chance) Dennis Wilson, one of the BeachBoys; thus, several bands have controversially covered his songs subsequently. He was also prosecuted by Vincent Bugliosi, who would go on to run for political office and write several books.
Manson is known because has was connected to other things that were bigger than him, be it the Beatles or Beach Boys.
LRM, by contrast, likely acted alone. No grand conspiracies to commit multiple murders. No cult. No commune. Unlike Manson, he doesn't appear to have any creativity beyond some cringe-inducingly bad YouTube videos which usually consist of 98% photos of him, some incoherent and vague text, or some incoherent rants on his website and/or blogs, much of which is plagiarized.
At the most, you could say LRM may to be the Internet's greatest troll ever, given the sheer magnitude of his online footprint and the vast number of accounts and sockpuppets and trolling he's done over the years. But I don't think his name will "be forever" connected to the Internet, any more than the Zodiac Killer's name was connected to newspapers (or the printing press!), to which he loved to write. That is, not at all.
Moreover, unlike the U.S., Canada, I think, does not glorify its criminals the way the U.S. does. Since he was convicted, Bernardo has basically disappeared.
LRM will be tried, convicted, and if we are lucky, we'll probably not hear a whole lot from him again. There will be a few sickos and weirdos who will glorify him on websites, but, really, no one will really notice.