After six years I renew my plead for a function ("soft select"?) that mirrors in 3D what Photoshop calls
"distort" - select a number of vertices, then adjust their overall volume and shape using the cursor.
Dennis' Box Conform could be a fairly good approach to this, but is somewhat limited (sorry Dennis...) and its use is less immediate than one might wish.
And I'd still celebrate with a bottle of good Champagne a
"bend along a path" function, conceptually similar to the "extrude along a path", yet picking up each new cross-section from an existing, multi-section cylindrical master-object rather than keeping it constant.
Most likely there would be some constraints (e.g. number of master sections = number of points in the path), but nobody would cry for that