Reports about the first month of that service are quite good. RZD eyes higher frequency, and gradual speeding over the next 2 years.
36hrs by 2013 is an ambitious target
...if they would serve cities such as London and Istanbul in the 10 coming years. Munich, Zurich and Geneva (+ St Gervais ;-) are also realistic targets. Barcelona/Madrid might be too much of a stretch, but never say never
The funny thing is that during Soviet times there were actually direct carriages from Moscow to Istanbul, London, Madrid, Rome and Geneva
I remember that. London was Hoek van Holland actually, while this time it could well be the Barlow trainshed of St-Pancras ;-)