I find I use 2 a lot - one for the actual signal, and often a 2nd so I see where it is occurring with respect to something known.
Hmm, sounds more like a 2-channel logic analyzer that way, which is how I have been using my scope actually.
Yeah, I think for strictly analog I am usually looking at audio stuff and then 1 channel is enough.
Will you be able to do some of the stuff that Visual Analyzer does?
http://www.sillanumsoft.org/prod01.htm
This is only sound card based, I have found it helpful working out where noise is coming from in analog circuits.