Paul Brossier recently announced on the music-ir list that his PhD thesis is available for download (PDF). The topic of his thesis is "Automatic Annotation of Musical Audio for Interactive Applications" where he deals with implementations of algorithms that have very short latencies (i.e. they are very fast, and don't require the whole audio file as input to create useful output). Update: see also this post at nest @ The Echo Nest.
Pedro Cano recently successfully defended his thesis in Barcelona. The topic of his thesis is "Content-Based Audio Search from Fingerprinting to Semantic Audio Retrieval" (PDF). He covers a broad range of topics and discusses issues such as the semantic gap. Pedro is currently CTO of BMAT which is an amazing MIR related startup with an unbelievable amount of funding and excellent links to the impressive MIR research group at MTG.
The list of MIR PhDs has been updated.