Link below is in Russian, but the jist of it is that the organisers of the protest march tomorrow have arranged to hold a funeral procession in his honour:
http://yodnews.ru/news/2015/02/28/vesna?nomr=1
I know we are all very obsessed with Putin, but it's important to realise that we don't know who ordered Nemtsov's death, and probably never will. I highly doubt this was instigated from the Kremlin as whoever killed Nemtsov would have been well aware that they were handing a martyr over to the protestors tomorrow.
What it does mean for Putin is that he now leads a country where opposition politicians are gunned down in the street, and for all the uproar it may cause tomorrow, it will also very likely cause a number of people sympathetic to Nemtsov to either shut up or emigrate if they can.
As my boss put it - "he'll be crying with one eye and winking with the other."