I posted this over at the rllmuk forums initially but it seems relavent to this thread as well.
Hopefully this answers your questions about the MP
F1 2010 has a variety of quick modes as well as the option to create your own custom GP tailored to your tastes. Here's a brief overview of the quick modes.
Quick Modes allow you to quickly enter a game without having to change multiple settings beforehand. Within the Quick Modes, all cars are of equal performance and team allocation
is random.
POLE POSITION
Pole Position replicates the intensity of
qualification. Each Pole Position race lasts
20 minutes and the winner is the player posting
the fastest lap time.
SPRINT
A single race of 3 laps duration, with dry weather and
with a randomised starting grid.
ENDURANCE
A single race of 20% length, with dynamic weather and
with a randomised starting grid; this race will include at
least one pit stop.
ONLINE GRAND PRIX
A single race of 7 laps duration, with dynamic weather.
The starting grid is determined by a 15 minute qualification
session and the player must pit at least once during the race.
Then on the other hand you have custom grand prix
Custom GRAND PRIX allows you to use your own settings to create an online game, or set specific search criteria to find a game already in progress.
For custom grand prix you can tailor such things as:
Race Length
Permitted assist level
Weather - Dynamic/Set
Fuel Simulation - On/Off
Tyre Simulation - On/Off
Damage Simulation - On/Visual Only/Off
Qualification Session - On/Off
Equal Car Performace - On/Off
Finally there is Time Trial Party, which enables you to compete against a group of friends on a single console/PC, with a single controller. Simply enter the mode, select the weather settings, number of players and attempts on each track, then compete amongst yourselves to take the fastest lap.
Oh, one final thing...I'll hopefully getting the official Steam F1 2010 community group started soon so make sure to keep an eye open for that!