I hear you on that. Solr only relatively recently got a decent, official Spatial search API with its version 3 release. We've got a Solr 3 cluster up at Websolr (with lots of other tasty stuff, like real-time updates), but Sunspot is lagging behind a bit.

I'm one of the maintainers of Sunspot and we're pushing out a new 1.3 maintenance/bugfix release within the next few days, which should clear the way for Solr 3 support -- and much better spatial search -- in Sunspot 1.4.