Summary: While it is possible to press "i" or right click and "Insert Keyframe" on the compositing nodes, the result will not render. The only time the interface refreshes is if you grab a curve spline and adjust.

Version: SVN 26198

Platform: Ubuntu 9.10 amd64

Reproduction: 1) In compositor view, add an image node. 2) Add a blur node. 3) Route image to blur and out to viewer. 4) On blur, insert a keyframe by pressing 'i' over the x value. 5) Scrub ahead to an advanced frame, and repeat by pressing 'i' and setting a high value. 6) Scrub back and forth or render. No change will be present in rendering or scrubbing.

Additional Information: I have only chosen to post this as a bug as Matt Ebb has stated that apparently things are supposed to be working. On the thread at BlenderNation Matt writes:

"Nodes are already properly animatable in SVN, there’s limited support in alpha 0 but that’s all been fixed up by now.

Just RMB on any UI control and choose ‘insert keyframe’. You can edit the keys in the graph editor/dopesheet like any other."