One way to get a conversation started is to bring up something the entire group has in common - in this case the "G" in GIS... and so the un-conversation continues.

[This started as a comment on Aaron's GISDevCafe, but got longish, and so it's here.]

I agree that there is something of a lack of cohesion and conversation between the various users/bloggers/analysts/forum-ers/managers/conference-ers etc involved in "GIS".  And I think the reason is quite simple - I believe that the GIS "world" is fracturing. Or, looking at it differently - people have been specializing. 

For a long time GIS users were all-around technologists. Pretty much everyone worked directly with data. We all handled weird projections and conversion of strange data formats. Serious thought was put into how to run an analysis because the processing would take so long that you could not simply run it again. Automation was limited but we did what we could and many poor souls took on sed, awk and grep with reckless abandon. Although we may have been using GIS for different purposes, we could all talk about the largely shared experience of "doing" GIS. 

Over the last 5 years, this specialization has been accelerating. I think this is especially prevalent in the developer community, where we have, by necessity, jumped into the software development/engineering pool. Heck we now have our own ESRI conference. The spatial analysis people have headed towards Model Builder / Python land and lived with days of processing time, or gotten all serious and hit it with C++ and GDAL/OGR to get some performance. Data Managers have become DBAs. The meta data crew are now working with Xml and Xslt .  And the web crew have ripped into Xml, REST, Javascript and Ajax. Hell - Google Maps pretty much defined "Web 2.0". Throw in open source & mashups and you've got quite a ruckus just in "online maps".

As for me, I spend much more time reading .NET & software development blogs than PlanetGeospatial or anything from ESRI. Sure the ESRI blogs are good, but they are still very much about the mechanics. I've specialized to the point that I know we can solve the mechanics (sometimes with hacks) but I want to know more about the best way to design the software - for testability, re-use and maintainability. And these topics are never discussed in the GIS "space". Thus, I spend my time and consequently my "conversations" at locations where these topics are discussed. And this same thing is going on all over the place. Specialization is rampant.

Add to that the fact that there are few really "new" core GIS concepts, and the "GIS Community" as a whole has little to talk about - other than ESRI licensing or other "shared experience" items - Google's new re-routing feature etc. We are now a whole set of smaller communities, specialized in our own areas, and united by the "where" of the data we work with. And Aaron put it quite nicely...

I see a microcosm of isolated islands loosely held together by the ocean of Geography

And essentially that's where we are - the "Archipelago of GIS".

Some may see this as "bad", but I don't think so. It's just a function of a maturing Information Technology sector. Back when Databases were the "new" thing I'm sure there were loads of discussions about all kinds of stuff - like normalization and set theory. Do you think DBA's are all yearning for those old days? Nah - I'm thinking they kinda like stuffing Xml documents into tables and being able to use SQL and XPath to query them and still getting response times only dreamed of back in the day.

GIS is merging into mainstream IT, and I for one welcome our new better-paying overlords.