as far as i know LR accepts other file types that Revel does not (such as RAW). But I'm not really a lightroom user. That you can answer. What I can say is that currently Revel only accepts JPG files.
The question was not about file types (I'm aware of the jpg only at this time issue), I want to know if it works with a pc or does it work only with a mac?
Yes you can use Lightroom 4 on the pc and connect to Revel to upload your images. Please see the following for instructions
Let me know if you have any other questions