Now that 'How I Met Your Mother's season 9 review has been made official, no more cast negotiations or delays about it, we doubt that this coming Monday's all-new episode "P.S. I Love You" will really prove the last we've seen of recurring gag Robin Sparkles. But throw in a cavalcade of Canadian stars, and what might be Robin Scherbatsky's alter-ego's most important appearance to date, and we're there! Check out a new preview clip of Robin Sparkles' return from Monday's 'How I Met Your Mother' episode "P.S. I Love You" inside!

Monday's all-new 'How I Met Your Mother' episode "PS I Love You" will revive the classic gag of Robin's Canadian pop star alter-ego Robin Sparkles for what would have been the last time, at least until CBS settled deals for a season 9 renewal. Nonetheless, the series has cobbled together an impressive amount of guest stars for what might be Robin Sparkles' most important appearance to date.

‘Growing Pains’ star Alan Thicke, ‘Late Show’ bandleader Paul Shaffer, ’90210′ hunk Jason Priestley, ‘Jeopardy’s Alex Trebek, K.D. Lang, Barenaked Ladies frontman Steven Page, Rush frontman Getty Lee and Canadian former hockey star Luc Robitaille will all appear as themselves, while ‘Dawson’s Creek’s James Van Der Beek’ will reprise his role as Robin’s old boyfriend Simon. Canadian actor Dave Thomas will portray music agent Chuck Gerusi, while ‘SNL‘ vet and Chris Elliot’s daughter Abby Elliot will appear as Ted’s new girlfriend Jeanette.

CBS today released a new clip from Monday's "P.S. I Love You," previewing the darker edge to Robin Sparkles, so take a look at the latest from 'How I Met Your Mother,' and give us your predictions for the season in the comments!