David Hurwitz is going to give a lecture/demo. on "the audible influence of Verdi and the Italian school on Mahler's musical idiom" at the University of Ediburgh. This is going to be a very, VERY interesting session. David has played me lots of examples over the telephone - mostly from Verdi & Donizetti - that indeed sound a lot like various passages in numerous works by Mahler.
http://sites.ace.ed.ac.uk/c19music/http://sites.ace.ed.ac.uk/c19music/files/2012/02/Conference-Programme5.pdfScroll down to session 21 on page 5.
Also, scroll down to session 30 on page 7. That might be interesting as well (Mahler Eight).