Would you recycle 3TC into a regimen containing AZT (or D4T), DDI (or DDC) and Sustiva in the presence of low level viremia (e.g. >50 but <500)? Might this be helpful in reducing VL since the M184V mutation reverses resistance to some other mutations, or might this be harmful since still more mutations could emerge that limit the future efficacy of combos with Tenofovir or newer NRTIs or NNRTIs under development?

I would not likely use 3TC in this setting if it was thought that drug resitance to 3TC had developed previously. I might introduce 3TC with Tenofovir in this setting, but this would depend on what other options/limitations were present in choosing a treatment regimen. Part of the reason to pick combinations that are more of a "sure thing" is to protect the other drugs in the regimen. So I try hard not to come close to an effective regimen, but rather aim for one that I have a greater degree of certainty with.