Like most applications today, switching between left and right tabs in a multiple-tab-interface is accomplished with Ctrl+PgUp and Ctrl+PgDn. This is the standard for the firefox web-browser and also gnome-terminal. This shortcut key, is honestly what's preventing me from switching to (gedit instead of nano) for regular usage, for everything from kernel development to writing down information for a daycare for my son.

I have two possible suggestions to increase usability. 

1) Use Ctrl+PgUp / Ctrl+PgDn for switching between left and right tabs, or
2) Allow keyboard shortcuts to be customized, a-la gnome-terminal

What would be a major step forward, actually, would be to have a gconf-centric scheme that would blanket all gnome-based applications with a default set of keyboard shortcuts, allowing manual override on an app-by-app basis. 

This would give gnome a consistent 'feel' throughout all applications, but also have the added benefit that users could customize it to fit their own needs. It would also make programmers' lives easier by abstracting out the keyboard shortcut management completely, for all gnome-apps, so it would only ever need to be programmed once. It would be easy enough to include a graphical tool for setting the keyboard shortcuts that could be dynamically linked-to from each app. 

As far as I know, this abstraction might (probably does?) already exist, so I would imagine, if utilized, that it would save the gedit developers and end users a bit of headache.

Cheers, C