During the past ten years, Wyner-Ziv video coding (WZVC) has gained a lot of research interests because of its unique characteristics of "simple encoding, complex decoding". However, the performance gap between WZVC and conventional video coding has never been closed to the point promised by the information theory. As a result, the enthusiasm about WZVC has stated to fade recently. In this paper, we illustrate the chicken-and-egg dilemma encountered in WZVC: high-efficiency WZVC requires good estimation of side information (SI); however, good SI estimation is not possible for the decoder without access to the decoded current frame. To resolve such a dilemma, we present and advocate a framework that explores an important concept of decoder-side progressive-learning. More specifically, a decoder-side multi-resolution motion refinement (MRMR) scheme is proposed, where the decoder is able to learn from the already-decoded lower-resolution data to refine the motion estimation (ME)...