If you're changing your oil every 3000-5000 miles and lubing and tensioning the chain every 400-600 miles you should be good up to north of 10,000 miles on most new modern bikes. The only other wear-and-tear items would be tires and brake pads, which obviously vary by type/use. I got about 8500 miles out of my stock brake pads (replaced with EBC HH Sintered) in mixed city/suburban riding (along with about 4000 miles of highway riding), and my tires still have healthy amounts of tread, though they are harder compound tires meant for lots of commuting.