If there was a port of the client for Second Life, could this lead to a virtual Warpstock?
Possibly, though I don't know if a Virtual Warpstock would do much or not. Much of the Warpstock experience is actually *being* there. Oftentimes, the presentations are springboards for the conversations that go on at Warpstock. To me, there are more interesting games than SecondLife available (I know they don't consider it a game).
I did not think of the virtual Warpstock as a replacement for the actual Warpstock. You are right, there is nothing like being there with others who know what OS/2 and actually use it. 
Warpstock Corporation - Forum
http://www.warpstock.org/forum/viewtopic.php?showtopic=275