I think it would be entirely possible to create a simple gesture editing tool with the current object editing interface, and I think this would open up a LOT of potential for things that are currently not possible (mainly posing for in game games and vehicles etc)
The way I see it working is that when you go into 'Gesture Edit' Mode, your avatar animations freeze, just like when you edit your appearance, but you are given an interface exactly like the object editor. But instead of moving objects, you simply select and move/rotate your various limbs into a position you want, then hit the 'save gesture' button and give it a name. It would perhaps appear in your inventory just like clothing.
... Which brings me to another idea. I would like to be able to set up a 'gesture set' for a given Av. I wear different Avs a lot, and I'd like to show different 'personalities' for each. To be able to use the Ctrl + G gesture setup thingy to make an explicit set that you could save in the clothing folder with your Av would, for me at least, be perfection on a stick.
It would also mean that, for instance, when you drag on your Jetball outfit that you instantly have a new reportoire of moves. Just think: you could learn Karate immediately by wearing a karate suit. Imagine if the gestures could be carried as content to an object? Imagine learning Karate moves stage by stage as you move up the belts from white, yellow, green etc...