We have a few of the van-mechanics here in Ottawa. No shortage of bike shops either though. The overhead on the mobile shop is so much less, and you can easily show up at locations where you'll get drop-ins - They'll often sit and park at popular bike spots during the weekend (parkways that are closed to cars for Sunday, especially).

Really too bad to see Harris Cyclery closing. I would echo the hopes that SheldonBrown.com is able to stay online.