Last week I was checking my iWave implementation from February. As you may remember it had quite strange issues: it kept emitting waves way too long after the obstacle had moved away, and sometimes waves seemed to move in wrong direction.
Finally I decided to implement another 2D wave algorithm instead. This time it's based on "Height Field Fluids" slides by Matthias Müller-Fischer. With some modifications it now works on mesh objects and is even compatible with new vertex surfaces.
Basic implementation is now ready and committed to soc-2011-carrot branch. It may still need some tweaking but unless something critical appears this should be about finished.
Here is a video showing a couple of test scenes:
If you want to try it yourself, here is a sample .blend file for carrot branch revisions 38044 and later.