"I think memetics can be saved because Polichak attacks a 
rather simplistic model ("the conduit metaphor"), though that 
is hardly his fault given the extent literature. We have to 
put memetics on a firmer foundation, and my guess it that can 
be done by developing a computational metaphor: 
memes are more like programs than genes or viruses."
I'm not sure that that solves the problem, Dave, because Aaron Lynch 
does already advocate a computational metaphor.  This came up during 
the long and heavy debate I had with him on the JoM mailing list this 
autumn.  The memetic 'programs' are then postulated to spread from host 
to host, or as Lynch would say, they are homoderivatively instantiated. 
The computer metaphor is therefore compatible with the 'conduit' model 
(or thought contagionist model or psychoepidemiological model or mind 
virological model etc.)
I see the criticisms in Skeptic as criticisms of the above models, and 
not of memetics as a whole.  There is another memetics which is 
behaviourist, empiricist etc and doesn't need either the virus metaphor 
or the computer metaphor (as I've been advocating through JoM this 
year, but I won't bore you with all that again......)  It's a pity 
(from my point of view) that Polichak thinks that memetics is just 
thought contagionism, but that's largely because Lynch has done such a 
good job of promoting his book (nothing wrong with that, of course, 
he's perfectly entitled to).  Polichak's view of the subject is 
therefore a bit one-sided, and any defence has to be based on that 
fact.
Derek