I guess another way to look at it is once Hubberts theory is validated globally, at that point all we WILL care about is net liquid fuels available to society, not whether Hubbert or anyone else was right.

Lately, Jean Laherrere try to apply the Hubbert approach on the forecasting of the "all liquids" peak that could include conventional oil, CTL, biomass liquids, etc.:

In 30 years petroleum will have become a little-used energy source (pdf file)

I personally find his article not very convincing.

It looks to me like an exercise in speculative curve fitting (extrapolating multiple overlapping Gaussian curves based on scant data).
Personally I find this article very convincing.

First of all Laherrère has data individually for each fuel source, something neither IEA nor EIA show us (at least monthly).

Secondly, Laherrère uses two different scenarios, a probable and an optimistic one (like Hubbert did in 1956). What you get from modeling things this way is peak around 2015, either with 1 TB or with 2 TB for all liquids minus crude.

Another thing worth mentioning is this: Laherrère, Deffeyes and Campbell are all putting the 50% Qt mark for Conventional Oil in 2005. And each of them is using different source data: Laherrère - IHS, Deffeyes - O&GJ, Campbell - Exxon(?).