Yes, #8 wire is rated for 40-50 Amps(actually 55 depending on the wire
type). This is from table 310.16, the 2005 National Electric Code for
the U.S. However, it completely depends how the original electrician
wired the building. Also, is the wire copper OR aluminum? If it's
aluminum, it will carry less amps. Will people be living full time in
the condos? Will they be cooking, using a washing machine, dishwasher,
hot water heater, individual air conditioning unit?

Is the number 8 wire running to supply each condo? Did anyone
calculate the load for each unit? I would think you need 75 to 100 Amp
service per unit. If each unit needs 75 amps, you probably need number
4 wire (copper) running to them. If 100 amps, number 3 wire. So, yes,
somebody may have made un gran error! But, it all depends.

And after that the wiring in the units to receptacles, etcetera is 14,
12, or 10?

Bottom line: Get a real electrician to help you before somebody gets
hurt!