Aside from "obvious" things like speed, accuracy, etc. what kinds of features do you really want in a terminal emulator (especially if you don't know of any terminals that do what you want)? What are a few really important things that just seem to have been dropped?
I develop a Mac terminal emulator, and a friend once asked me why. His reasoning was that the OS already had one, and that seems to be a recurring theme with bundled software: people don't tend to ask for features beyond what OS-bundled apps already provide. So I thought I would finally ask; are people really content with what's there out of the box?
I can't really think of anything else in a terminal program that I'd look for. Good font rendering, obviously. Huge scrollback buffers would be nice. Maybe better copy-paste handling?
I can still use MacOS X's built-in terminal app, and I often do when working on a client's computer, but it feels really inelegant now by comparison. A little like having to give up your favorite ratcheting box wrench set for standard combo wrenches.