It's sort of surprising that no one has mentioned this already...
Today, Secretary of Defense Robert Gates and Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff appear before the Senate Armed Services Committee to present a plan on how the military will deal with a post-DADT world. According to
this Time article, both Gates and Mullen are on board with the repeal, which should quell some of the worries of fence-sitters who don't want to scrap the law without the support of the military.
The major question seems to be not if but when DADT will end. Despite their support for the repeal, both Gates and Mullen advocate a slow repeal, to give time to deal with some of the issues that having openly gay servicemembers will bring up. In the meantime, while it appears that there will be no suspension of DADT investigations and discharges, they are proposing changes to make it much more difficult to launch an investigation and discharging them.
Given that, at least publicly, President Obama didn't do much to advocate gay rights during his first year, the fact that this hearing is happening less than a week after his State of the Union address is surprising and gratifying. We're not out of the woods yet, but it looks like we can finally start to write the obituary for Don't Ask Don't Tell.