Hello SMW devs...
I'm the developer of the Semantic Layers extension ( http://www.mediawiki.org/wiki/Extension:Semantic_Layers ), which you may have seen via my post on semediawiki-users. If not, its an extension that integrates the OpenLayers web mapping API with SMW. It has a number of interesting features, including a mechanism to easily group and display placemarks (wiki articles with Type:Geographic coordinate attributes in them), ways to define placemark, image overlay, and tiled imagery layers in the wiki, and--most pertinent at the moment--the ability to write a SMW-style query and have the results returned displayed on a map.
I'm writing for a couple of reasons: First, to see if anyone on the list has tried out my extension, and/or had a look at its code, and might have any feedback for me. I'd be glad to hear any suggestions or constructive criticism.
Specifically, I am interested in feedback on the way I used SMW in the back-end. Namely, I don't access the SQL database directly--I use SMW's query parser. Unfortunately, to do this, I had to make a copy of the SMWInlineQuery class and add my own method (getResult) to it, based on getHTMLResult (extending the class didn't work, since key members are private instead of protected). My "enhanced" version of the class allows me to pass along a query to SMW and programmatically iterate through the results.
Along those lines, I am curious if a similar capability the one I've created is forthcoming in SMW 1.0? Or has it been considered?
Additionally, another feature I'd like to add to my extension in the future is a KML and/or WFS export capability for placemarks defined by users in the wiki. If you're familiar with KML, it has a feature called "Super Overlays", which allows for progressive disclosure as you zoom in--basically, in Google Earth, when farther away from the surface you might see fewer placemarks, but when closer, more would appear--it's a way to control the density of information on the screen. To accomplish this, however, would require the capability to query the geographic data based on a bounding box--e.g. return all articles with placemarks in the rectangle having lower-left corner 0,0 and upper-right corner 45,45 (degrees). Currently, in v0.7, geographic coordinates stored in the database are not stored in a way that would seem to make this practical. Has this type of feature (querying based on the location of geographic coordinate attributes) been discussed/planned for 1.0? It would be a great boon to my extension and I imagine many other types of applications.
Again, any comments appreciated.

-Matt Williamson