Many dont need 1080P with smaller monitors and even some Projector reviews cant really see a difference from 8 to 10 ft away on super large screens no matter how much those who own BR insist its worlds better, 720 to 1080 isnt a huge leap and on a moniotr of say 50in or less its a non issue IMO.
I would jump for BR if you want as its gonna be better than 480P and still better than even upsample units, also dont forget the better HD audio formats you can enjoy with HDMI capable reciever or a internal decoding BR player hooked into a reciever or Processor with multi channel RCA bypass. Also it will likely upsample standard DVD's.