Over 10 years ago I started out in GIS using MapInfo MapX VB application running on MS Access backend database.
Since then my programming career moved away from GIS and MS languages and into Java and open source technologies. As I'm considering moving back into GIS, I need to make some strategic decisions on where to focus my attention. What seems apparent is that I'm potentially moving from a very broad market into a niche area. Finding those niches seems challenging, but it's something I'd like to pursue; my academic background is originally in Geography/Earth Sciences. I'd be interested to get some insight into the key growth areas/technologies in GIS if possible... I'd like to stay in open source and Java, building on my skills, but applying them to GIS. It seems there are quite a few Java APIs for GIS around, which is encouraging. Should I read PostGIS in Action first, or start somewhere else with other reading / online resources.