i don't think The Hours is just another suicide movie, as its plot outline describes it. i haven't read the book but as i watched the film, i could definitely sense some sort of intuitive understanding of it.
the title itself, and some particularly telling dialogue (how Clarissa thinks Richard's "look" means she preoccupies herself too much with triviality) highlights a fact of life most people (including the woman her self!) commonly do not pay attention to-- a woman's life.
a woman's life is generally made up of the little moments, "the hours", those seemingly insignificant, trivial and dull moments of picking out flowers to buy, baking a cake, talking with a friend, being there for a suffering friend, planning a party (interestingly, with all activities usually devoted to giving, caring, making somebody else happy)-- which still ultimately defines the quality of her whole life.
if the moments, the hours, are the hours she has freely and consciously chosen (Laura saying, "what shall we do today?") then it becomes an empowering and full life for her (is she happy too? does she find joy in doing those things that she has decided to do, whether consciously or by default?); if the hours are dictated by what she "must do" (but that she doesn't really find joy in doing) as a wife, mother, daughter, friend, then it could become a limiting and deadening life for her (Virginia Woolf at the train station, explaining to her husband how it feels to be living a life she did not choose for her self).
as i understand it, suicide can also be the ultimate act of self-reclamation. when you are feeling helpless and powerless about many aspects of your life, it can be the final liberating and empowering moment, taking back what was rightfully yours in the first place.
so i viewed this as a movie about three women who struggled and dealt with, in their own way, the deadening effects of a sanitized life-- whether caused by the small-mindedness of social mores and conventions about how a woman should be, that nameless emptiness one feels in a lonely marriage, or the prison of regret over what could have been and trying to make up for it for the rest of one's life.
indeed, it is a disturbing movie (some reviewed it as "confusing", as they couldn't make heads or tails of it), because it takes us to something which we commonly ignore and forces us to take a look at it again and re-think what it means again. (look at your wife, mother, sister, girl friend again, and ponder what she does with her hours, and whether she's happy with them... or, if you're a woman, too, look at your life again!)
Brent Trafton is also right in saying that it is a movie for people who care enough to think about the movie and what it means long after they have left the theatre.