From time to time I want to use vim as scratch pad for commands that I would like to send to a command line shell like
ghci (Haskell programming language),
gnuplot (plot) etc.
The advantages would be that you could put comments next to command lines, directly document your session, incrementally develop command lines, test examples ad-hoc in manuals etc.
Pro features I would like to use: send a selection to a shell, send e.g. the next 10 lines to a shell, display the output of a shell command into a vim output buffer, into a vim yank-register, directly insert it etc.
There should be some support of a shell-session concept, i.e. the shell should not be started for each command from scratch.
I could live with a kind of remote controlled xterm which I would put side by side to a vim window.