Thanks for reading. I just bought a PS3 a few weeks ago. I have a question about blu ray. My 50 inch plasma only out puts 1080i

A 1080p set is a year away. Here is my question that I have asked before on different sites but could not get an answer.
Does a blu ray movie look "better" at 1080i than a regular Dvd upconverted to 1080i?
On a side note the blu ray promos look incredible on my set.
Thanks for your help.
DB