yeah, i can relate. i've never gotten rid of one of my bikes voluntarily (had 2 stolen long ago)... i currently have 4:

i still have my 1st mountain bike - '89 Stumpjumper which is now my short-distance-commuter bike w/o clipless pedals for when i want to wear regular clothes or need to park in 'unsafe' places.

then my roadbike... '98 Raleigh w/ Campy/Sachs

then my old MTB - '98 Norco Torrent w/ RockShox Judy which i now use as my main commuter for getting to work - it's also used when friends visit from out of town w/o a bike

and my new 2002 Specialized FSR XC Comp which i only use off-road

it's great being able to do a ride or a commute w/o having to change tires or take off a rack or riding knobies on the road or my commuter tires in the mud -- also, only my off-road bike gets the major abuse - i find i rarely have to replace things on my commuters or road bike - back when i only had one it was a pain b/c almost every week i broke something mountain-biking and then had to commute with a blown rim or messed-up drivetrain until i found time to fix it.

then if i even want to build up a singlespeed or a trials bike or whatever i have a lot to work with...

i still love all my bikes and with so many miles on each, each has so many memories andit's just not worth the few hundred bucks i might get selling one.

i haven't had a car in 11 months now! but i do have 4 bikes, 1 push scooter, 2 pair rollerblades, snowboard, skiis, rock-climbing shoes, etc.

i'll bet your old bike will still get plenty of use. My old old MTB still gets around 1000km/year