Well, if we were all immortal, meaning we couldn't die and had no need of things like air or food etc, then we could easily colonize other planets and expand as necessary. Some people would be put on ships to distant galaxies. However, if we were immortal from the beginning, then we'd have inter-stellar traval capabilities since we'd advance much faster technologically seeing as how war is more than just pointless.
In that case, the entire universe would be at our disposal. We'd be able to live on a sun if need be...though you didn't say whether we could experience pain or not. xd