Little seems to have been said about this in Russian press or anywhere. Thanks to colleagues for the tip off. The following is a translation of the first few paragraphs. The original can be found here in Russian:

New Year – New Terror: Nazis Film Themselves Committing Murder

(FONTANKA.RU) – A provocative film of nationalist character was uploaded to the Internet just before New Year’s by a group called NS-WP. In the video, a guy in a mask greets his “like-minded brothers” and calls them to commit terror. Typical for these types of sites. But with a nuance — in their declaration, the extremists claimed responsibility for the murder of Ghanaian citizen in the Moskovsky district on December 25, 2009 and published a video of the attack. The police say the video truly shows the incident occurring at the end of 2009.

On December 25, 2009 at around 21:30, Solomon Attengo Guadjo, a twenty-five year old Ghanaian citizen, was hospitalized at city hospital no. 26 in extremely critical condition. Medics registered around forty stab wounds to his head, neck, chest, stomach and limbs. He died at 04:40. Police have opened a criminal murder investigation.

The attack could have become one of the biggest crimes of the end of the year. However in the flurry of New Year’s preparations and celebrations, the law-enforcement agencies of St. Petersburg already had a headache over something else: personnel were providing security at mass events, and dealing with the effects of domestic drunkenness. St. Petersburg journalists also paid scant attention to the attack. Therefore, the declaration by the nationalist group NS-WP (National-Socialism White-Power) in the internet in which they claimed responsibility for the murder of the foreigner went practically unnoticed by any competent authorities. It was the video that added credibility to the pathetic declaration.

Further reading in Russian #1
Further reading in Russian #2
–

A colleague had this to add: The African Union in St. Petersburg said that the man was not from Ghana, but an illegal immigrant from Nigeria. After the attack, his friends got scared and left the flat (outside of which the attack occurred) immediately. The African Union President said that these guys were also illegal Nigerians and have already been arrested by the Russian police because they don’t have documents to live in Russia. Now they are in a jail. Currently, there are no other sources of information about this killing. The police are trying not to give out information.