I have a 1993ish Litespeed MTB and it is all the MTB I will ever need. And my advice, diplomatically turned, is to screw the Pugsley. I also find them interesting and, though I have never ridden one, tend to agree with those who point out the incredible amount of mass in the wheels and the effect on performance. Instead, I suggest that you build out the Litespeed with drops and barends, and get an extra set of wheels -- fatties on one set and 26" 1.35" CX tires on the other. I suspect you would ride that bike far more than a Pugsley.
I understand why you're saying that, but I think a Puglsey would be more fun - and capable of doing some things this wouldn't be capable of. I rode one last year and have wanted one ever since.