A bit of background. The Finnish parliament (Eduskunta in Finnish, Riksdagen in Swedish) is a unicameral body, consisting of 200 MPs. Elections are held every four years, with the country being divided into 15 electoral districts, each district electing a number of MPs, in proportion to the number of people living in that district (there's one exception; the Åland Islands, an autonomous region of Finland, forms its own electoral district which elects exactly one MP).

"The big three" of Finnish political parties are the Centre Party, the Social Democratic Party and the National Coalition Party (right-wing); their numbers are such that Finnish governments typically consists of any two of them plus one or more of the smaller parties. In the last election in 2003 the big three received 24.7%, 24.5% and 18.6% of the votes, respectively.

Besides those three, there are currently five other smaller parties in parliament: the Left Alliance (former Communists), the Green League, the Christian Democratic Party, Swedish People's Party (Swedish minority party/liberals) and the True Finns (nationalist euroskeptics). The Left and the Greens have been coalition partners in one or two governments in recent years, and the Swedes have served in every single Finnish government since 1979. The current government consists of the Centre, the SDP and the Swedes.

Finnish elections are typically fairly tame affairs, with the big three being rather civil to one another, presumably because if they are to govern together in some fashion after the election, they can't have pissed each other off too much during the campaign. A consequence of this is that regardless of which two (or three) eventually end up in the government, the policies advocated by the government are rarely radical departures from previously beaten paths.

A notable exception is 2003, when then Centre Party leader Anneli Jäätteenmäki accused then SDP leader and Prime Minister Paavo Lipponen of having promised George W Bush that Finland would join the then budding coalition of the willing in invading Iraq. Jäätteenmäki had based this information on classified documents she shouldn't have been reading. The Centre Party subsequently won the election, and Jäätteenmäki became Prime Minister, Finland thus having both a female President and a female PM, but Irak-gate, as the affair has been dubbed, broke shortly after her taking office, and her initial denials lead to such a loss of confidence that it forced her to resign a mere few months into her tenure (Matti Vanhanen became PM and Centre Party leader in her place, and is still serving in that capacity today).

The 2007 campaign features some sparks as well. The SDP's campaign focuses on the ideological divide between left and right, with simple ads proclaiming the red-colored "us" (the collective) to be larger than the blue-colored "I" (the individual).
The trade unions managed to shoot themselves in the foot by producing an attack ad, purporting to show a caricature of the typical Capitalist, feasting on copious amounts of food and generally behaving in a pig-like manner. The ad caused such a backlash it had to be pulled before being aired on television. What effect, if any, it'll have remains to be seen.

Issues? Taxes and welfare, I suppose. The parties on the right want tax cuts, whereas the parties on the left want to extend the welfare state. The usual stuff.

Current polling has the Centre Party in a slight lead, followed by the Social Democratic Party and the National Coalition Party, that is, largely as in the current parliament, though with the Social Democrats losing a few percentage points and the National Coalition Party gaining a bit.