I'm probably in quite a good position to comment on this, as I don't use a mouse and use both OS X and Windows 7.
It was only when I got a Windows 7 laptop a couple of months ago and a Wacom Intuos5 Touch more recently that I realised just how good Apple's Trackpad and Magic Trackpad are. The Apple Trackpad never sticks, both my Samsung Notebook and the Intuos5 Touch occasionally stick, you move your finger and nothing happens. Another problem is that they don't get the "Tap to Click" right, you get too many unintended clicks, I never experience these with either the Trackpad on my MBP, or my Magic Trackpad.
The biggest issue with using Trackpads with 3D applications (but not TG!) is lack of MMB support. On OS X I use MagicPrefs
http://magicprefs.com/ to emulate MMB using 3 finger click then releasing 2 fingers and dragging with the remaining finger to zoom or whatever. On Windows 7 I haven't found a similar solution, so I use the Intuos5 for applicaitons, like Houdini, that absolutely require a MMB.
In terms of TG the keyboard navigation, whereby you can use LMB with key combinations, is one of the best solutions I've seen in any 3D applications (I use CINEMA 4D, Houdini, and modo). I also use the Compass quite a lot. I would like to see a mini compass for the Network window for GUI consistency (a feature for Terragen 3 perhaps!).
I don't miss the gestures when using TG.
I find some of the gestures a nuisance, as what makes sense on a touchscreen often makes rather less sense on a trackpad. I seem to get unintended actions from gestures more frequently than intended ones.
I suspect that the best course of action would be to do nothing and wait and see how this area evolves once people start using Windows 8.
I wonder if Microsoft will release a trackpad alongside or soon after Windows 8, it seems a pretty obvious thing for them to do. There mouse is very popular.