While I’m not a particular fan of this exact idea (renaming println! to print! or Python’s end=""), it does occur to me that println! sounds like a misnomer: it doesn’t “print a line”, as it could print a multi-line string. Instead, it “prints a string plus a newline”. I can’t think of any good alternative naming, off the top of my head. It probably isn’t worth bikeshedding, as there are plenty of people coming in from Java and other languages which already use the println convention.
Aside: if one is heavily using println! to print things out in their code, in many cases they could use the log crate for more informative logging, anyway: log!, debug!, info!, warn!, and error!.