The nix shell command replaces nix-shell -p to provide a shell in which the specified packages are available. However, the name nix shell is confusing since there are also development shells (created by nix develop), which this isn't; and the old nix-shell by default does start a development shell. So we should come up with a better name. Some suggestions have been made:

• nix load nixpkgs#git - "load" a package into the current shell. This one mainly makes sense in the context of updating the current shell, rather than starting a subshell.
• nix push nixpkgs#git / nix pop - update the current shell to add a package to the environment (similar to pushd / popd)
• nix use nixpkgs#git - "use" is probably too ambiguous though.
• nix add nixpkgs#git - probably sounds too permanent.
• nix bonk nixpkgs#git - random name with no connotations that forces people to read the manpage.