and the shift away from W*S architecture continues

On the Safe blog, Paul Nalos writes about Iowa DOT's data publishing strategy:

Second – and this is where it gets really interesting – they presented an approach where multiple data sources are fused together in the visualization stage. The idea is that it is easier to query multiple data sources (e.g., using web services) in the visualization layer than to keep composite or centralized data stores in sync. Merging data this late in the game likely doesn’t make sense in all cases (e.g., if complex analysis or transformation is required), but the basic advantages are clear: users benefit from an integrated display of data in one system when they would previously have consulted two.

"An integrated display of data" sounds a lot like a tile cache.