A lot of projects can drop the acronym, but frankly I doubt many of the projects cited as using RDF would actually validate as true RDF. For example, how does a true RDF parser deal with RSS? Show me some cross-domain communication that works, and does useful work, and then maybe I'll stop saying that RDF is DOA.
Most of the projects Shelley mentions use RDF in their core, and it's as true as it gets.
Re. cross-domain communication, many of the apps listed in [1] have some cross-domain element (virtually every RDF app uses DC for a start!).
RSS is something of a special case, but RSS 1.0 *is* true RDF, and as I point at [2], other RSS dialects can be transformed to RDF. Note also that the Raptor RDF parser now has a "tag soup" facility for handling other RSS dialects and producing true RDF.
NewsMonster [3] is one example (there are others) of an app that uses RSS and cross-domain RDF.
It's way too late too talk of RDF being DOA, it's adoption is accelerating. Check out Dave Beckett's resource list [4].