http://www.caa.co.uk/docs/175/srg_fcl_Notex_A1_2005.pdf
I would also be interested in references or comments from other instructors.
The above is clearly a guidance note but perhaps is indicative of things to come and is also more of a guidance note in that it implies unless a FI meets the requirements then he is not entitled to give difference training on these types - difference because of FADEC, or glass cockpits, and as I commented earlier are the differences requirements or recommendations of the CAA, the insureres or just the clubs.