So I just upgraded to Emacs 22 in April, despite Debian Etch not supporting it. It solves several of my daily annoyances with Emacs 21: - It recognizes "Password: " as a password prompt, so ssh and sudo get the benefit of me not having to manually type M-x send-invisible. - I can paste Unicode text into it from a web browser, including asymmetrical quotes, real apostrophes, and em dashes, and have it save them to a UTF-8 file without fuss. (Although it still displays the quotes in an obnoxious double-width fashion until the file has been saved and reloaded.) - TRAMP works out of the box. - The documentation is included, unlike in Debian. (There's a licensing dispute over whether the GNU Free Documentation License is free enough to satisfy the Debian Free Software Definition.) - comment-region now asks what comment syntax to use if it doesn't know. - When I run e.g. "darcs" by itself in shell-mode, occasionally Emacs used to take quite a while to display its output usage message, because it was reading it one character at a time. This has been fixed.
I also anticipate joy using MuMaMo, but I haven't actually tried that yet.
There are some changelog/news entries that sounded pretty good:
...if you set `set-mark-command-repeat-pop' to t. I.e. C-u C-SPC
C-SPC C-SPC ... cycles through the mark ring. Use C-u C-u C-SPC
to set the mark immediately after a jump. [Haven't tried this yet.]
...M-% typed in isearch mode invokes `query-replace' or
`query-replace-regexp' (depending on search mode) with the current
search string used as the string to replace. [Haven't tried this
yet.]
You can now customize the use of window fringes. To control this
for all frames, use M-x fringe-mode or the Show/Hide submenu
of... [so now I can have two 80-column windows on my screen at
once, which is awesome]
A new minor mode `next-error-follow-minor-mode' ... In this mode,
cursor motion in the buffer causes automatic display in another
window of the corresponding matches, compilation errors,
etc. [Haven't tried this.]
The new command `multi-occur' is just like `occur', except it can
search multiple buffers. [Useful. Also I didn't know about
`occur`.]
The grep commands provide highlighting support. Hits are fontified
in green, and hits in binary files in orange. Grep buffers can be
saved and automatically revisited. [This is in fact extremely
awesome.]
In addition, when ending or calling a macro with C-x e, the macro
can be repeated immediately by typing just the `e'. [This sounds
nice, but the F3 and F4 macro keybindings are better.]
The new package longlines.el provides ... "soft word wrap" [like
actual word processors have since the 1970s. Turns out to be
fantastic.]
SES mode (ses-mode) is a new major mode for creating and editing
spreadsheet files. [Haven't tried this yet.]
The new package table.el implements editable, WYSIWYG, embedded
`text tables' in Emacs buffers [Haven't tried this yet.]
The new package flymake.el does on-the-fly syntax checking of
program source files. [Haven't tried this yet.]
savehist saves minibuffer histories between sessions. [Haven't
tried this yet.]
isearch in Info uses Info-search and searches through multiple
nodes. [This is fantastic.]
Atomic change groups: To perform some changes in the current
buffer "atomically" so that they either all succeed or are all
undone, use `atomic-change-group' around the code that makes
changes. [Sounds like a fantastic idea, but I haven't tried it
either.]
So far I've only noticed two new annoyances: one is that it uses its own python-mode that I don't like as well as the one that comes with Python, and the other is that C-x C-f RET no longer reverts the file to the version in the filesystem (assuming the buffer wasn't edited); now you actually have to type the filename.
The stuff in the NEWS file (C-h N) looks pretty innocuous. Nothing is terribly exciting, though.