I know I have patted my vehicles and thanked them for their service, but I haven't done it much ot my bikes. My VW I said lots of kind things to it, but it was my first car and we shared alot of good times together and I had it almost 9 years. I didn't cry when it left (Insurance totaled it and gave me more than it was worth even to me) but I surely felt a loss when it was gone.
I have too many bikes and cycle through ones I am working on to really get attached to any one I think. My Trek Police bike is probably the one I have the most affection for. I doubt I'll ever be able to get rid of it.