We currently tween the map on panning, but offer no control over how we do it. Rather than scatter options throughout many different functions, we should investigate having a map-level option for controlling the tweening and options to tweening.
I think that most important for the 2.6 release is just a way to turn it *off*, since there are cases where it doesn't make sense for an application: this could be done by setting a tween/tweenClass option to 'null', which would change panTo to just call setCenter instead.
I think not having a way to turn off tweening is a blocker for 2.6: I didn't feel this way until recently, when I started working with large vector datasets, where tweening the pans via the pan button don't make sense.