They are interchangable and it can be done that way but if you just wire for a chandelier you won't have two seperate switches (1 for the light and 1 for the fan). There would only be one switch which would control the chandelier. If you switched to a ceiling fan afterward because you only have one switch, which would either control the fan or the light (not both), that would leave you having to purchase a fan with a remote control. If you pre-wire for a fan with two switches to begin with all of your options are covered up front. Hope I'm making sense! :)

I completely agree with lynninnm and les. I hate overhead bedroom light fixtures and any place we have lived I have immediately replaced the ceiling light, if there was one, with a fan (with no lights). We use the fan year-round. Ceiling lights, no matter the wattage, are cold and harsh and you need additional lamps in the room anyway. We have night table lamps which are similar to the size we have on living room end tables and a floor lamp in the sitting area of the MBR. Warm lighting is so much nicer than a cold overhead light, imo, so enjoy sleeping with a fan and scrap the ceiling fixture.

I replaced a ceiling fan with a chandelier in my guest room and still wanted guests to have the option of a fan. It took me over a year to locate it, but this is a Casablanca fan that works like a dream, doesn't make much noise, and is very heavy. They make other models, more contemporary.

I think this is a style preference. Some tray ceilings are absolutely beautiful but are expensive because there's so much detail. If it's done more economically, then it's best not to bother. To take a way the stark look if you have a plain ceiling, I suggest a simple but large-scale crown moulding to define the transition.