I might have my conspiracy theorist goggles on, but when you think about it, Yes-Man 'advises' you on what to do next for every quest. Since Yes-Man seems like a true A.I. akin to JHE from Fallout 3, I have to wonder if Yes-Man just needed a human patsy so that he could surreptitiously take control of Vegas. I also just now thought of something. House didn't seem to concerned with Yes-Man existing when you mentioned him, so what if he somehow coded this 'personality trait' and purposely left it to leave a Neuro Computational Maxtrix copy of Houses Brainwaves, essentially turning him into a Machine God Messiah should the true Mr. House die?
-Puts on the tinfoil hat-
-Puts on the tinfoil hat-
In some ways (however minor) it resembles 'Bioshock' in which Atlas was always asking you "would you kindly".. do this, do that..
As for NV, I don't trust anyone other than my character.. although in my playthroughs I've never ever taken the Legion route and never will.. that faction to me and especially Caesar are totally ridiculous and should be used for nothing else other than target practice.