The opposition APC has to convince voters it represents genuine change, while the ruling PDP will have to persuade voters to stick with the devil they have come to know so well.
The formation of the opposition All Progressives Congress (APC) in February last year represented a landmark event in Nigerian politics. For the first time since the country's return to multi-party democracy in 1999, the dominance of the ruling People's Democratic Party looked like it could be seriously challenged.
The APC resulted from the merger of four main opposition groups and is essentially the first challenger party with a national scope. Historically, party politics in Nigeria has consisted of one 'national' party and a few others with more regional outlooks.
This was the case in the so-called First Republic (1963-6) and the Second Republic (1979-1983). In the Third Republic, the annulled elections of June 1993 were contested by two national parties - the National Republican Convention (NRC) and the Social Democratic Party (SDP) - but these were essentially creations of General Ibrahim Babangida's regime and were roundly dismissed by critics as 'test tube parties'.
In the Fourth Republic (1999-now), there have been attempts to create genuine challengers to the PDP. Days before the 2011 elections, for example, some opposition parties tried - and failed - to join forces. Even if they had, the PDP's march to victory looked all but inevitable.
Now, however, some lessons seem to have been learned. Opposition groups have been able to put aside their differences - at least for now - and form early enough before the 2015 elections to develop an alternative platform from which to woo voters and smooth out any internal cracks before it's too late.
There is much discontent in Nigeria with the PDP. Various high-level officials have been implicated in corruption scandals, the government has been unable to ensure economic growth is inclusive and leads to employment, and President Goodluck Jonathan has failed to stem the tide of attacks by the Islamist militants Boko Haram.
However, disillusionment with the PDP does not necessarily mean victory for the APC come 2015.
The opposition party has its own issues with which to contend. Last year, for example, the APC welcomed a wave of defectors from the ruling party, including 5 governors, 37 members of the House of Representatives and around two dozen senators. On the one hand, this was a political coup and marked a changing of the tides.
But on the other, it left some wondering how different the APC could be to the ruling party if it was drawing so much of its line-up from the PDP.
One way in which the APC could distinguish itself is through its choice of presidential candidate and, crucially, in the process by which that choice is made.
As a party whose slogan is 'A new party for a new Nigeria', the APC needs to pick a nominee who can embody this sense of change as well as connect with voters.
However, once again, its strength in being able to boast an array of well-recognised political veterans could prove to be a weakness if not handled sensitively. For a long time, the PDP somehow managed to keep the many factions within the party happy; now the APC must do same.
Securing credible elections
For all the attention on the PDP and APC, the two giant parties are not the only organisations that will determine the outcome of the 2015 elections.
The Independent National Electoral Commission (INEC) will also play a key role, especially given how competitive and potentially close the polls could be.
The first challenge will be financial. According to INEC's chairman, Attahiru Jega, running the election will cost N92.9 billion ($570 million). However, given that the 2011 elections in the Democratic Republic of Congo, which has a population less than half the size of Nigeria's, cost $360 million, that figure could end up being significantly higher.
The second challenge for INEC is to ensure the elections are credible. At the beginning of April, federal lawmakers continued to debate changes to electoral law that would place the burden of proof on INEC in election petitions.
If implemented, this would mean that INEC would have to show an election was credible when challenged. Only once it did this would the petitioner be required to provide evidence that the poll was not conducted properly. It is hoped that this arrangement would put even more pressure on INEC to ensure free, fair and credible elections.
The messy and disputed governorship elections in Anambra state last November raised serious concerns about the commission's capacity.
Jega has said the lessons have been learnt, but this assertion will soon be tested in the governorship elections in Ekiti and Osun, to be held on 21 June and 9 August respectively.
The American author Mark Twain is often credited with coming up with the saying: "Politicians are like diapers. They should be changed often, and for the same reason".
One thing this points to is the fact that while, in an electoral democracy, people may vote out bad leaders, they will not necessarily vote in good ones. Hence the need to repeat the process often.
Since 1999, Nigerians have not really had this opportunity. Although the man at the head of the PDP has changed, the ruling party has not.
Now, for the first time, Nigerians could decide that 15 years of PDP rule is enough and that they are ready to try something new.
Over the next ten months, the APC will have to try to convince voters that they are indeed something new, while the PDP will have to try to regain the people's trust or at least convince them to stick with the devil they have come to know so well.
Jamie Goode is a freelance analyst. He has lived and worked in Nigeria as well as representing the nation on the rugby pitch. In 2005 he wrote and presented the documentary 'This is Lagos'.