Dave: are you refering to the crude graphics or to the long time line of developement goals.
I see from the side bar of images for lunar base designs that a few are of the inflatable type. I would think, that this would not be very practical since it would be easily damaged by micro meteors and other impacts.
I think a more modular design with our partners from the ISS each giving a section to create this base would help to defray the overal cost but I also think that it should be core complete by the date 2023 not just starting.

From what I have read on TransHab it should actually be more resistant to micro meteorites than aliminium used currently. The poly-hydrocarbons used are also better insulators against radiation.

The big problem with "inflatables" are that you cannot pre-construct anything - all the interior features will need to be added later - a logistical nightmare, potentially risky - but great for modularity & mass production of the inflatables.

Ok now that I did some homework on Transhab I can now speak of it. The TransHab, a habitation module designed for the ISS but scuttled in March 2023 to help trim growing ISS costs were included in the International Space Station program's budget, but is was not manifested for launch during the stations construction. Critics say TransHab should be funded within NASA's Human Exploration and Development (HEADS) program at some future time, not with the space station. Composed primarily of multi-layered fabric, foam and Kevlar, the major component of most bulletproof vests. A shell of carbon composite ribs maintains the shape of the module.
Transhab image http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=v_astrotel_transhab_02.jpg∩=The%20inside%20of%20the%20Astrotel%20would%20resemble%20this%20scrapped%20NASA%20design%20for%20an%20ISS%20TransHab%20module
Another company thinking along the same lines was Global Aerospace Corporation with a design called Astrotel, a 10-passenger flying Motel 6 that never stops moving
Astrotel image
http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=h_astrotel_inflight_02.jpg∩=One%20concept%20for%20an%20Astrotel%20along%20with%20a%20Taxi%20docked%20at%20one%20end
Both were in the news back in 1999 but seemed have been killed in favor of aluminum cans instead.

Erik: You have voiced much of what others and myself have already stated in previous weblogs.
The other draw backs not mentioned must still include foam falling off the external tank, of which NASA still has no solution for along with the Presidents vision stating a complete shut down of the shuttle operation by 2013. The Nasa problems are that if it is not designed by them it seems that they do not want it.
The exploration time line for the Manned version of the CEV would not be due until 2018 for use as indicated in the Nasa planning steps to the Moon office of exploration program overview on page 5.
I agree that we must do something now to take the shuttles place, since it does not seem to be a viable solution at this point in time for access to space and may not in the future as well.

Here is a site if you long for Mars habitat designs http://www.exploremarsnow.org/