Another link to the pdf version of the 2010 SPARK Ada presentation:
http://www.disca.upv.es/jorge/ae2010/slides/IP1-2_Wedin_MDA_and_SPARK.pdf
There have also been two presentations performed regarding Ada & xtUML and VHDL & xtUML at the Shlaer Mellor User Group in 2004. Unfortunately I have not been able to find them on the net.
