Unless that reference to the first film goes along the lines of, "Guess what? Jim Phelps wasn't the bad guy after all!", I don't see myself ever mustering up any enthusiasm.
Phelps is never referenced one way or the other in any of the sequels. As I said, except for one passing reference to the iconic Langley break-in scene from the first movie, the later films in the series are essentially completely unconnected to the first film in any way. The first three movies aren't a series, they're three totally independent spy thrillers whose lead characters happen to have the same name and which are very loosely and superficially inspired by the same TV show. Only movies III through V are a series.
Look, I'm as displeased by what the first film did with Phelps as you are, but it has no bearing on the later films. The writers and director of the first film have had nothing to do with any of the later films; the only people they have in common are Tom Cruise (as star and producer), Paula Wagner (Cruise's producing partner on the first three films), and Ving Rhames. Both the second and third films are essentially soft reboots from different creative teams, and the rest of the series has followed on the third film. Refusing to watch movies III-V because you didn't like the first movie is kind of like refusing to watch the Marvel Cinematic Universe because you didn't like the Ang Lee
Hulk movie. Yes, they have a character in common and draw on some of the same source material, but they're different takes on the premise from different creators.
it's really easy to just 'forget' the first two and pretend Jim Phelps retired and lived a long and happy life.
And of course the M:I universe is fraught with impostors. It's easy enough to assume that Jon Voight's "Phelps" was an impostor who'd infiltrated the IMF. I like to think that the mission Ethan was offered in the closing scene of the first film was the rescue of the real Jim Phelps.
Although I'm unconvinced that the movie series is in the same continuity as the TV series. There's never been a cast member from the original reprising his or her role (the first film pretty much burned that bridge) or a direct reference to any of its characters or events other than Phelps, who was unrecognizable aside from the name (and was really a lot more like Dan Briggs, Phelps's predecessor from seaosn 1). Moreover, in
Rogue Nation, Brandt says the IMF has existed for 40 years, and the original series ran from 49 to 42 years ago. There's never been any clear suggestion that the movies were a continuation rather than a reboot.
I'm with Christopher on really only liking them from 3 onwards. My big problem with the earlier ones was I didn't think much of Hunt. He wasn't unlikeable (except a little bit in the 2nd), but I just didn't think he had much personality and I couldn't invest in him. It basically felt like 'Tom Cruise! In the role of Protagonist-that-makes-the-plot- happen!'.
Yup -- he had no discernible personality in the first two films, no emotional depth. He was just the guy that stuff happened to. What makes the third movie such a breath of fresh air is that it finally turns him into a full-fledged, relatable, three-dimensional human being, all within the first ten minutes of the film, so that for the first time in the series you actually care about what happens to him and the people in his life. My biggest disappointment with
Rogue Nation is that, unlike
Ghost Protocol, it doesn't really continue that deeper characterization of Ethan, painting him more as just a maverick agent who's intensely driven by a personal vendetta against the bad guys.