The newest episode was a cliff hanger to lead into Season 9. We see Robin and Barney grow closer together as they attempt to break up an annoying couple. Marshall and Lily are at a crossroads where Lily has a job in Rome and Marshall has been offered a Judge position in New York. Ted is about to meet the woman he would eventually marry and finally tell us How He Met his Kids Mother.
at birth
imdb.com
No
Judy Greer plays Royce in the episode "The Wedding Bride" of How I Met Your Mother.
Doppelgangers (Season 5, Episode 24)
Amanda Peet
It was called "Intervention"
That is Stacy Keibler who played the role of Karina in episode 100 of How I Met Your Mother. She has appeared in numerous other shows as well such as Chuck.
It was Season 5, episode 12, Girls vs. Suits.
Season 5, episode 17 - Of Course
The last episode of How I Met Your Mother has not aired yet. The producing team have made mention that the next season, 8 may be their last season.
Hooked - Season 5