According to an unidentified Russian naval official, two Russian warships with an accompanying force of marines will head to Syria under the pretext of protecting Russian citizens in the country. But the real purpose for this naval expedition is likely for the purpose of bolstering Assad's increasingly isolated regime in Syria.
The two warships, which the New York Times has identified as "amphibious assault ships" laden with a unspecified number of Russian marines, are scheduled to land in Tartus, the second largest port in Syria, to dock at a Cold War-era naval base. The mission of the Russian marines is not clear, though one may speculate that they will likely provide support to the Assad regime and serve as a deterrent to Western powers who are tempted to intervene in Syria.
The Russian naval official explained that the naval mission "jointly with the marine units they carry are capable of protecting the security of Russian citizens and evacuating a part of the property of the logistics base." This makes it seem like Russian intervention in favor of Assad will become a stronger possibility.
A comparable instance occurred in the 2011 NATO airstrike as China evacuated its citizens from Libya prior to the start of the campaign. In that instance, China's evacuation was limited to military transports and civilian charter ships from Greece with one warship acting in a protective role. Though some pondered the implications of such an efficient military-like operation, the operation went off with little hints of Chinese support for the Gaddafi regime.
Russia has a vested interest in the survival of the Assad regime, especially given the large volumes of arms that Russia sells to Syria and the importance that Syria plays in Russia's Middle East policy. Russia is Syria's biggest supplier of arms and munitions, including powerful attack helicopters, which the Assad regime has used to suppress the Free Syrian Army.
This isn't the first military expedition Russia has mobilized in support of Assad since the unrest in Syria began last year. Towards the end of November Russia sent its flagship aircraft carrier to Tartus in a "show of solidarity with the Syrian people," a move which Western media saw as seeking to deter Western powers from openly intervening in Syria and potentially toppling the Assad Regime.
To be sure, one cannot say with any great certainty that the Russians plan to get involved in the suppression of the rebel forces in Syria, but the presence of Russian warships and ground forces will certainly make the West likely hinder any form of open support in the Free Syrian Army's fight against the Assad regime.