I have yet to see a really decent analysis of what the problems would be if there were no barrier to open gays in the military
Did you read the Prakash essay in Joint Force Quarterly that came out earlier this month?

Crux of the issue - what do we gain and / or what do we lose concerning this issue? Is it really a generational issue or are the naysayers being forcefully cut out of the debate?
Seems like 13000 troops is a pretty big loss, and millions of dollars is nothing to sneeze at either. Quoted from the Prakash essay:

In a report released in February 2005,
the Government Accountability Office
(GAO) estimated the financial impact to be
at least $190.5 million for the previous 10
years of DADT policy. However, a University
of California Blue Ribbon Commission that
included former Secretary of Defense William
Perry questioned the report’s methodology.
The commission faulted the GAO for not
including recruiting and separation costs that
brought the 10-year estimate to $363 million.15
Also worth noting is that these figures do
not account for the additional opportunity
costs of high-profile, prized specialties such as
Arabic speakers.
You can find the Fall JFQ here.