[edit] Blender NLA Editor
May be Blender NLA (Non Linear Animation) Editor (groups of repeatable animations with groups blending) can give some ideas: http://mediawiki.blender.org/index.php/Manual/Non_Linear_Animation
The Ipo Curve Editor: http://mediawiki.blender.org/index.php/Manual/Ipo_Curves_and_Keyframes