I have great news - an SMW-related project has been accepted among the Wikimedia Foundation's four Google Summer of Code projects.
So, I'd like to introduce Jeroen De Dauw to everyone - he's the student who will be working on this project. Jeroen is a college student in Belgium, and an open-source and wiki enthusiast. And I believe our two first names are pronounced almost exactly the same - which may or may not help anyone wondering how to pronounce them. :) I think he'll do a great job.
As to the project - the goal is to create an extension called "Semantic Maps", that, going forward, will hold support for all mapping services. It will hold a different directory for each mapping service, in a manner similar to Semantic Result Formats; and it's meant to replace the current Semantic Google Maps and Semantic Layers. The first steps are to create the extension, with support for Google Maps and OpenLayers (the service that Semantic Layers is built around); we have the full approval of Matt Williamson, the developer of Semantic Layers, for the latter. After this is accomplished, with time permitting, Jeroen will also add handling for Google Earth and Yahoo! Maps; and, if there's still time after that, more geocoding options. As you might guess, I'll be serving as the mentor for the project.
If you're wondering about the Google Summer of Code, you can read more about it here.  This will be the second SMW-related project in the GSoC - the first was a project to add RDFa support to SMW, last summer - although this is the first that's one of the Wikimedia Foundation's projects; the last one was run by Creative Commons.
By the way, you may wonder why all this mapping code isn't getting added directly to Semantic Result Formats instead: it's because mapping code also defines two other things besides query formats - parser functions to display a single point, and form inputs. I think a separate extension makes more sense, although other opinions are welcome.