This is in advance of the official announcement of the election results (which I assume is in the MDC’s favor). Ironically, it took place at a swiftly called press conference at South Africa’s main airport, as President-elect Tsvangirai has been in Botswana waiting for results.

BBC NEWS | Africa | Opposition reunites in Zimbabwe
Zimbabwes divided opposition says it has reunited, declaring a majority in the countrys parliament.
The announcement was made by Movement for Democratic Change MDC leader Morgan Tsvangirai and his former rival Arthur Mutambara.