Oddly enough, I have a feeling it might depend on how well Without A Trace: Season 1 sold (that set came out September 7th). Both series are produced by Warner Brothers, but air on CBS. Both series are also fairly similar in their genre/style, so the fan base is likely similar as well.
However, Warner has been really good to its TV properties though, so I wouldn't be surprised to see an announcement sometime soon. Of course, this is all just rampant speculation on my part, I don't have any inside info one way or another.
With Cold Case, I hope they worked out the music rights to future home releases at production time. Otherwise, with the amount of music this show has (especially a lot of popular songs to "set the time period" of each episode) it would be nearly impossible to release it unaltered .....
That's gotta be pretty much standard practice now, expecially for a new that debuted after the boom in TV on DVD start. The only reason shows like Miami Vice and The Wonder Years had an issue was that they were made before video releases of TV series were even conceived.