No need to submit a feature request. It's a common request, and (iirc) will probably be in TM 2, but certainly not before then. See
http://macromates.com/wiki/Requests/, number 16.
I guess one option is to submit a feature request for some extra
swankiness to be included in an upcoming version :-)
I sometimes wish you could do split pane editing, but on the rare
occasions I really need to do that, I use an editor called "Kate"
which is part of linux's KDE suite. I installed it via fink (cause the
fink version is newer than the macports one) and can happily edit away
in split pane, side by side etc when I need to.