What do you want to do with the bike(s)? Purely recreational/leisure riding? Is bike-commuting in your near or somewhat-near future?

I have kept my Trek 7100 hybrid when I switched to a road bike four years ago... and started using it again last week for my new, longer-distance commute. I certainly would not let the road bike go, but for city use, running errands, commuting, and going everywhere, that specific hybrid (I've had others) is hard to beat.

So I'm partial to keeping two bikes, but it really depends on your plans.